Abarim Publications' online Biblical Hebrew Dictionary
It's not clear whether the root זהה (zhh) has ever existed; most dictionaries don't list it. Here at Abarim Publications we're pretty sure it once existed. The Arabic equivalent of our root, spelled in Hebrew characters, is זתת (ztt; the ה and the ת alternated over time) and it means to adorn or to beautify.
The Hebrew root זהה (zhh), however, must have had to do with emerging fresh or being new or even tender and vulnerable or something like that, which is not the same but also not too far removed from its Arabic counterpart.
Apart from some names (see below) the only obvious, albeit disputed, derivation of our root is the masculine noun זית (zayit), meaning olive tree:
The olive tree in the Bible
The Hebrew word for olive tree is זית (zayit (Deuteronomy 8:8, 2 Kings 18:32, Amos 4:9), or the fruit of it; olives (Amos 6:15) and olive-oil (שמן זית, shemen zayit; Exodus 27:20, Leviticus 24:2).
A person who occupied any of the few highest earthly ranks — the king, high priest and a prophet had no earthly superiors — was called an anointed (see the name Messiah), and anointing was done with olive oil (Judges 9:9). A failure of the olive harvest was a disaster because that would mean that Israel's social structure couldn't be maintained (Deuteronomy 28:40).
And it also caused the olive tree to be one of the most symbolical entities in the Bible. What is symbolizes, however, is commonly not very well understood, but it's by no means an accident that Jesus' passion began with His arrest on Mount Olivet.
The dove and the olive branch
That the symbolism of the olive is really quite complicated is demonstrated in the story of Noah, where after the flood a released dove returns to the Ark with in her mouth a עלה-זית טרף, ('ayle-zayit tarap; Genesis 8:11), which literally means: the violently torn leafage of an olive (tree), but which translations of the Bible usually generously interpret as a freshly picked olive leaf.
This image has further been developed into a dove carrying a whole olive branch, which then became interpreted as a symbol of peace. But this evolution is faithful only to that odd human persistence to warp whatever is out there into whatever we want. In short: Noah's dove has not a thing to do with offering peace to anyone.
The word יונה (yona; see the name Jonah), meaning dove, is closely similar to יון (yawen) meaning mire or being without foothold, and even ינה (yana), meaning to vex, oppress or wrong someone. The earth had been flooded for 150 days (Genesis 8:3). The Ark wrecked on Ararat in the seventh month, and in the tenth month the tops of the mountains became visible (8:5). Forty-seven days later, the dove came back with our 'ayle-zayit tarap in her beak. And whatever that was, it certainly was not a freshly picked leaf from a cheerfully blooming olive tree.
Whatever remained of the drowned olive trees was at that time still below a vast amount of water. It took three whole months for the water to recede the height of the draught of the Ark (three months between running aground and seeing the ground). Forty-seven days after that there were only high mountain summits above water. What the dove had managed to harvest was a hardy helping of whatever little plants or mosses had sprouted on the mountain tops.
Ergo: the word by which the Hebrews knew the olive also meant something more basic, namely a freshling, or firstling, or even herald of a lot more to come. And that's not all that odd, as we shall see.
The olive as firstling
Our English word olive comes from the Latin oliva, which is thought to be a transliteration of the Greek word ελαια (elaia), and although in many languages the word for oil derives from olive, they both stem from a more basic idea.
The olive tree was known as a firstling or the one that gets things going probably for several reasons. It was one of the first plants to be domesticated, and the cultivation of it on an industrial scale was a major catalysts for the wealth and cultural evolution of southern Europe and the Levant (Deuteronomy 6:11, 1 Samuel 8:14, 2 Kings 5:26). Canaan was not only a land of milk and honey, also of olives (Deuteronomy 8:8).
Among the oldest living organisms on earth are olive trees; some of them are thousands of years old and still yielding crops (read our article on the name Gethsemane). Crop yielding commonly happens only once in two years and a production cycle starts with the budding of a vast amount of blossoms. Olive yields are normally enormous for a healthy olive tree, but in spring an olive tree carries many more blossoms than there will be olives as many of the blossoms will fall off before turning into olives (Job 15:33).
This appearance of vast amounts of flowers was among the primary signs that spring, the commencement of the agricultural year, had come (Song of Songs 2:12, Hosea 14:6). The month of spring (April-May) was in Canaan known as Ziv (זו), which we here at Abarim Publications suspect to come from the same root זהה (zhh) as does our word זית (zayit). The month Ziv was thus the month of sprouting, whereas the olive was the sprouter. Note that the name Ziv is spelled the same as a rare variant of the demonstrative pronoun זה (zeh) or זאת (zo't), meaning this or which.
Olives and temples
The month of Ziv (the "second" month) is mentioned in only one context in the Bible, namely as the month in which Solomon commenced building the temple of YHWH (1 Kings 6:1 and 6:37). Seven years later, but in the month Bul (the eighth month; October-November, or harvest) it was completed. It's overly obvious that the building of the temple in Jerusalem reflected the agricultural year, or rather: a Sabbath cycle (Exodus 23:11) combined with the agricultural year. And it also manifested the Feast of Booths, also known as the Feast of Harvest (Exodus 23:16), during which the Israelites were to live in booths for seven days.
These booths were made from the branches of various trees, including the olive (Nehemiah 8:15), which explains why there were so many around during Jesus' triumphant entry (John 12:13). That entry resulted in Jesus execution, which resulted in the commencement of the building of the final, living temple of YHWH (1 Peter 2:5). But calling this entry "triumphant" might be a bit of a misnomer; the people were crying Hosanna, which isn't a merry cheer like Hallelujah but a desperate cry meaning "help us, please!"
In the natural world, a dove has three priorities: get food, get safe and get offspring. Noah's dove had lived safely and well-fed for many months in the Ark, and we may assume that whatever it brought back to Noah was intended for a nest; the dove's nest's very first twig. Noah's dove was building a house; the Holy Spirit assumed the form of a dove when He descended on Jesus (Matthew 3:16). This same Spirit formed the church, which is a living temple (John 2:21, 1 Corinthians 3:16).
All in all it's becoming clear that in the Bible the olive symbolizes commencement and the frailty, helplessness and vulnerability thereof (Psalm 52:8, 128:3), from the tiniest sprouts of new life after the flood, to the yearly returning spring, to the beginning of the building of Solomon's stone temple, to the utter feeble entry of Jesus into Jerusalem, which constitutes the beginning of the building of the final temple.
(The olive branch returns in the troublesome vision of Zechariah, in which the prophet sees two of them flanking the Menorah (Zechariah 4:12). These two also represent a beginning, and again of the temple, see Zechariah 4:9. Here at Abarim Publications we foster neither allegiance to what is commonly believed nor fear of being called insane, but we're pretty sure that Zechariah 4 is one of a few places in the Bible that describe DNA. If you haven't already, you should probably read this website's front page.)