Abarim Publications' online Biblical Hebrew Dictionary
The verb כמה (kama) appears only once in the Bible, namely in Psalm 63:1, where the Psalmist is in a dry and waterless place and exclaims that his soul ... [yearns/thirsts?] ... for God.
In cognate languages this verb means to be gray, weak-eyed or blind, and thus in general to be deprived of light. There is an obvious link between wisdom and light in the Bible, but also between water and wisdom (see our article on the verb נהר, nahar, which means to flow, both of water and of light).
Our verb expresses a yearning for insight, using the metaphor of water, but the very fact that it's used only once in the entire Bible shows that this verb also uses a highly specialized form of yearning or thirsting, for which no proper equivalent exists in English.
The Hebrews knew that light comes from the sun but water cycles on earth, and water in the Bible always points toward, quite literally, liquidity (i.e. the trade and exchange) of wisdom rather than knowledge itself or the produce that ultimately grows from a well-lit and well-watered society. The Psalmist yearns not so much for insight or the result of insight but rather the exchange of insight, as opposed to the prolific dispensation of lies he mentions in the Psalm's final verse.
Also note the similarity between this verb and the comparative particle כמו (kemo), meaning like or as if. It combines the more common particle of comparison כ (ke) and the particle of inquiry מו (mo), meaning "what?".