word-forming element in science meaning "rain," from Greek hyetos "rain," from hyein "to rain," from PIE root *seue- (2) "take liquid" (see sup (v.2)).
Entries linking to hyeto-
sup v.2
"to sip, to take into the mouth with the lips," Old English supan (West Saxon), suppan, supian (Northumbrian) "to sip, taste, drink, swallow" (strong verb, past tense seap, past participle sopen), from Proto-Germanic *supanan (source also of Old Norse supa "to sip, drink," Middle Low German supen, Dutch zuipen "to drink, tipple," Old High German sufan, German saufen "to drink, booze"), from PIE *sub-, possibly an extended form of root *seue- (2) "to take liquid" (source also of Sanskrit sunoti "presses out juice," soma; Avestan haoma, Persian hom "juice;" Greek huetos "rain," huein "to rain;" Latin sugere "to suck," succus "juice, sap;" Lithuanian sula "flowing sap;" Old Church Slavonic soku "sap," susati "suck;" Middle Irish suth "sap;" Old English seaw "sap").
hyetal adj.
"of or relating to rain," 1855, American English, from Greek hyetos "rain" (see hyeto-) + -al (1).