The headword is the masculine/feminine nominative singular of the two-ending adjective polughqh/s, -es; see LSJ s.v., and, for the substantive part of it, cf. gamma 231, gamma 232, gamma 233. The feminine nominative plural form appears in the phrase polughqe/es w(=rai, delightful seasons, at Homer, Iliad 21.450 (web address 1); cf. the scholia there.
[1] The gloss (see LSJ s.v.), a later compound with the verb xai/rw (I rejoice, I delight; cf. LSJ s.v.), is of the same grammatical form as the headword; cf. E.A. Sophocles (in Bibliography below), p. 909. The headword is identically glossed in Photius' Lexicon (pi1034 Theodoridis), Synagoge pi532, and Lexica Segueriana 345.17. The neuter nominative/accusative singular of the lemma appears in Hesychius s.v. polughqe/s with corresponding gloss.