LSJ
τό, a swelling of the glands, esp. of the groin or armpit, Ruf. ap. Orib. 44.21.1, Heliod. ap. Sch. ad l.c. (iii p. 687 D.); also spelt φύγεθλον, Gal. 11.72; Lat. phygetron, Cels. 5.18.19, 28.10. (Perh. for φλύγεθρον, cf. φλυκτίς.)
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)