The noun υπνος (hupnos) means sleep, which is a hitherto unexplained condition of the mind in whose unconsciousness we exist about a third of our time here on earth. Our English word "hypnosis" comes from this noun, and both stem from the Proto-Indo-European noun "supnos", sleep, from the verb "swep-", to sleep (hence too our English verb to sleep). Curiously, there is no parent verb to this noun — the derived verb υπνοω (hupnoo), describes a putting to sleep, but not the action of sleeping itself. This verb does not occur in the New Testament (but see αφυπνοω, aphupnoo, below). The verb used for to sleep is ευδω (heudo), see further below.

The Hebrew equivalent of our noun is שנא (shena'), which comes from the verb ישן (yashen), to sleep. This verb is closely associated with the verb שנן (shanan), which speaks of repetition (and learning from repetition). This is significant because the verb to dream, namely חלם (halam), is closely associated to חול (hul), which denotes a whirling or circular motion.

The Greeks personified sleep as the god Hypnos, who lived in the underworld with his twin brother Thanatos (Death personified), which suggests an association with the preposition υπο (hupo), under or below.

In the Hebrew model, dry land was associated with consciousness, and cities with the formal stories from which we weave our conscious realities. Sleep and thus the sub- and unconscious were subsequently associated with the sea, which explains both the existence of "waters under the earth" (Exodus 20:4), and the "fishers of men" that the disciples would be (Matthew 4:19). But it also equates sleep to not having words to establish a formal definition of something encountered, which means that this something can't be discussed or shared with someone. And that in turn equates waking from sleep to the formalization of thoughts for which no words or descriptions existed (Matthew 1:24).

Jesus' father Joseph was able to save Jesus from the wrath of Herod by doing what his famous namesake had done two millennia earlier: explain his dream (οναρ, onar). Quite telling, in his adulthood, Jesus rode triumphantly into Jerusalem upon an οναριον (onarion), which is a little donkey, not a little dream (pun doubtlessly intended).

Our noun υπνος (hupnos) occurs 6 times in the New Testament; see full concordance, and from it derive:

The verb ευδω (heudo) means to sleep, and occurs in the New Testament only combined with the prefix κατα (kata), meaning down from, down upon: καθευδω (katheudo), to lay down to sleep. It's unclear where this verb came from (and thus what it precisely described) but some commentators insist that it stems from the Proto-Indo-European verb "swep-", to sleep, that came with the noun "supnos", hence υπνος (hupnos), meaning sleep (see above).

How ευδω (heudo) evolved from "swep-" remains a mystery, and since everybody is guessing, here at Abarim Publications we guess that the formation of our verb may have been helped along by the ancients' clear understanding of the hydrological cycle and their application of it to the cognitive cycle (and see for more on this, our article on the noun νεφελη, nephele, meaning cloud).

More specifically, the form of our verb ευδω (heudo) may have gravitated toward a group of words that combines the prefix ευ (eu), meaning good, with the root of the genitive of the name Zeus, namely Dios (Διος), which in turn comes from an ancient Proto-Indo-European root that expressed brightness of sky: noun ευδια (eudia) means fair weather; verb ευδιαω (eudiao) means to be fair or calm; adjective ευδιαζω (eudiazo) means calm or still. The somewhat reminiscent adjective ευδωρος (eudoros), well-giving or generous, combines our prefix ευ (eu) with the noun δωρον (doron), meaning offering of gift.

Most generally, our verb describes existence in a mental state that is signified by a temporary unawareness of reality as shared by awake or woke bystanders. It's used 22 times; see full concordance and has no derivatives.