hay n.

Old English heawan "to chop, hack, gash, strike with a cutting weapon or tool" (class VII strong verb; past tense heow, past participle heawen), earlier geheawan, from Proto-Germanic *hawwanan (source also of Old Norse hoggva, Old Frisian hawa, Old Saxon hauwan, Middle Dutch hauwen, Dutch houwen, Old High German houwan, German hauen "to cut, strike, hew"), from PIE *kau- "to hew, strike," a root more widely developed in Slavic (source also of Old Church Slavonic kovo, Lithuanian kauti "to strike, beat, fight;" Polish kuć "to forge," Russian kovat' "to strike, hammer, forge;" Latin cudere "to strike, beat;" Middle Irish cuad "beat, fight").

Weak past participle hewede appeared 14c., but hasn't yet entirely displaced hewn. Seemingly contradictory sense of "hold fast, stick to" (in phrase hew to), 1891, developed from earlier figurative phrase hew to the line "stick to a course," literally "cut evenly with an axe or saw." Related: Hewed; hewing.

also hay-fever, 1825, from hay + fever. Also called summer catarrh (1828); not much noted before the 1820s, when it was sometimes derided as a "fashion" in disease.

People are apt to sneeze, in hot weather for example; and people do not die of sneezing now-a-days, as they did in days that no one knows any thing about. We cannot give six draughts a-day, at one and nine pence each, for sneezing: call it the hay-fever. What a wonderful man! what a clever man! he understands the hay-fever: call him in! Thus is the hay-fever among the last in the list of fashionables. ["On Fashions in Physic," London Magazine, October 1825]