suckyoudaoicibaDictYouDict[suck 词源字典]
suck: [OE] Suck is part of a widespread Indo- European family of ‘suck’-words which go back to the base *seug-, *seuk-. This no doubt originated in imitation of the sound of sucking from the mother’s breast. Amongst its relatives are Latin sūgere (whose past participle sūctus gave English suction [17]), Welsh sugno, German saugen, Dutch zuigen, Swedish suga, and Danish suge. Suckle [15] was probably a back-formation from suckling [13], itself a derivative of suck.

Also from suck comes sucker [14], which originally denoted a ‘baby still at the breast’; its use for a ‘gullible person’ (that is, someone as naive as an unweaned child) originated in American English in the early 19th century.
=> suction, suckle[suck etymology, suck origin, 英语词源]
suck (v.)youdaoicibaDictYouDict
Old English sucan "to suck," from a Germanic root of imitative origin (cognates: Old Saxon, Old High German sugan, Old Norse suga, Danish suge, Swedish suga, Middle Dutch sughen, Dutch zuigen, German saugen "to suck"), possibly from the same source as Latin sugere "to suck," succus "juice, sap;" Old Irish sugim, Welsh sugno "to suck;" see sup (v.2). As a noun from c. 1300.

Meaning "do fellatio" is first recorded 1928. Slang sense of "be contemptible" first attested 1971 (the underlying notion is of fellatio). Related: Sucked; sucking. Suck eggs is from 1906. Suck hind tit "be inferior" is American English slang first recorded 1940.
The old, old saying that the runt pig always sucks the hind teat is not so far wrong, as it quite approximates the condition that exists. ["The Chester White Journal," April 1921]