Abarim Publications' online Biblical Hebrew Dictionary
Linguists count two separate roots קוה (qawa), but they might as well count three, or only one:
The root-verb קוה (qawa I) probably originally meant to twist or stretch (or so sayeth BDB Theological Dictionary), and from that tensive meaning our verb came to denote to eagerly wait for, or wait with steadfast endurance. This verb yields the following derivations:
- The masculine noun קו (qaw), meaning line or measuring line (which either reflects the verb's original meaning, or is from a whole separate root all together). This noun occurs little over a dozen times in the Bible (Isaiah 28:17, Job 38:5).
- The masculine noun קוה (qow), a rarer variant form of the previous noun. It's used three times: Zechariah 1:16, 1 Kings 7:23 and Jeremiah 31:39.
- The masculine noun קוקו (qawqaw), meaning might or strength. This word occurs twice, in Isaiah 18:2 and 18:7.
- The masculine noun מקוה (miqweh), meaning hope (1 Chronicles 29:15, Ezra 10:2).
- The feminine noun תקוה (tiqwah), meaning cord. This noun is used in Joshua 2:18 and 2:21 only.
- The exactly identical feminine noun תקוה (tiqwah), but now meaning hope (Jeremiah 31:17, Job 4:6, Ezekiel 19:5).
The root-verb קוה (qawa II) means to collect or gather. It's probably indeed a whole other root, but it should be noted that when a rope is twisted so that it becomes a tensive coil, it also quite gathers up onto itself. In the sense of collecting or gathering, this verb occurs only three times in the Bible: in Genesis 1:9 the waters are gathered into one place; in Jeremiah 3:17 nations are gathered, and in Isaiah 60:9 ships gather. This root has two derivatives:
- The masculine noun מקוה (miqweh), meaning collection or collected mass (Genesis 1:10, Exodus 7:19).
- The feminine noun מקוה (miqwa), meaning reservoir (Isaiah 22:11 only).