Abarim Publications' online Biblical Hebrew Dictionary
The masculine noun בן (ben), most generally meaning son, occurs thousands of times in the Bible (including the plural בנים and construct-plural בני, meaning 'sons of'). That alone shows how important family is in the Bible, and partly explains how the relationship between God and mankind became understood as that of a father and son.
But it should be realized that the word בן (ben) is by no means as narrowly defined as our word son is. And as common as our word is, we have no idea how we got it. BDB Theological Dictionary rattles off a vast array of obscure researchers and impenetrable abbreviations but grimly observes that "all traces of this root are lost in Hebrew form".
The brilliant Bible scholar Wilhelm Gesenius, however, quietly proposed that בן (ben) may have originated in the root בנה (bana), meaning build or rebuild. This verb usually simply refers to the building of buildings, but since a man's "house" most often denotes the family that lives in the house, rather than the actual building, the connection with the word בן (ben) is defendable with a great deal of optimism. The optimism rises even higher when we observe that in Genesis 16:2 Sarai, until then barren and desiring sons at any cost, addresses her husband Abram, shoves her aid Hagar front-center and utters the words, "Please go into my maid; perhaps I shall be built up from her," using our verb bana. The plural of בן (ben), namely בנים is spelled the same as the word meaning 'builders' (1 Kings 5:8, 2 Kings 12:11, Ezekiel 27:4).
This at once directs our attention towards the curious statement made by Jesus:" . . . for I say to you that God is able from these stones to raise up children to Abraham" (Matthew 3:9), which is now far less curious and all the more profound.
Note that some scholars propose that the word for stone, אבן ('eben) is also related to the verb בנה (bana), meaning to build, and thus to our noun בן (ben), meaning son.
The word "house" is often used to denote someone's family. But it's also used to denote any other clearly defined group, such as a guild, a caste or order, and the word בן (ben) denotes a member of that group. Hence the Bible speaks of sons of the prophets (1 Kings 20:35), sons of the troops (2 Chronicles 25:13), sons of the exile (Ezra 4:1), even sons of transience (Proverbs 31:8).
The word בן (ben) is not even solely reserved for males. In Genesis 3:16 God informs Eve that she will suffer labor pains due to giving birth to benim, which certainly denotes both boys and girls. The word בן (ben) is not even reserved for humans (calves are 'sons' of the flocks - 1 Samuel 14:32), or even living things ('sons' of the sparks - Job 5:7; kernels on the threshing floor are 'sons' of the floor - Isaiah 21:10). A yearling kid may be called a son-of-year (Exodus 12:5) and offshoots of plants may be called their daughters (Genesis 49:22).
So yes, the word בן (ben) means son, but it really means quantum or building block.
It gets even more interesting when we look at the plural of the word בן (ben); as in Genesis 5:4, "and he had other sons and daughters". For 'sons' we see the common masculine plural: בנים (benim) and for daughters we see the common feminine plural of the same word: בנות (benut). In other words, the Hebrew word for daughters is the feminine form of the word for sons. Something similar happens in Dutch where the word for boy (jongen) literally means 'young one' and the plural (jongeren) indeed means 'young ones' and covers both young men and young women (the opposite of jongeren is ouderen, from 'old'). In Hebrew, however, the plural for daughter (בנות) is identical to a common expression of the verb בנה (bana), meaning to build (Joshua 22:23, 1 Samuel 14:35, 1 Kings 3:1).
The singular form for daughter appears to be a contraction of the plural word benut, namely בת (bat). And that is not at all peculiar. In the Bible a group of people (which consists of many benim) is feminine, and not only in some vague grammatical sense. The word for people (nation/ tribe) is אמה ('umma) and the word for mother-city (as used in 2 Samuel 8:1) is אמה ('amma). Both are closely related to the word אם ('em), meaning mother. This word אם ('em), meaning mother, is even directly applied to cities and their townsfolk (Isaiah 50:1, Ezekiel 16:44, Hosea 2:2).
On the same note, Israel as a nation is frequently compared to a bride, and more specifically, to the bride of God (Ezekiel 16:8). Similarly, believers who are gathered into the Body of Christ are also depicted as bride (Revelation 21:2, John 3:29).
We should also note that the Hebrew word for house (temple, family, group), בית (bayit), which contracts to beth in compound names such as Bethlehem or Bethel, bears a striking resemblance to our word בת (bat), meaning daughter. The prophet Isaiah speaks of בית־ציון, which literally reads 'House of Zion', but all popular modern translations interpret this as 'daughter of Zion' (Isaiah 10:31).
The masculine plural of the word בן (ben) is בנים (benim). But in compounds or constructs (like: sons-of-Israel), the final mem drops off: בני ישראל (benay-Israel).
There are about half a dozen of names in the Bible that consist of the letter ב (beth), followed by a regular word that is sometimes also a name. This prefixed ב may either be the particle ב (be) that means in or via (as is the case with the first letter of the Bible), or it is a contracted form of our word בן (ben). Something similar happens with patronyms in modern languages where names like William's Son or Mac-Phail were compressed into Wilsen and Quayle. See the list of B-names below; names that don't start with, or end on ben or bar are (perhaps) of this contracted patronym form.