ὑπαν-οίγω · hypan-oigō — LSJ
open from below, tap a cask, βῖκος ὑπανεῴγνυτο Ephipp. 8.2, cf. Hermipp. 82.7 (hex.).
open underhand or secretly, [γράμματα] ὑπανέῳγεν D. 32.28; τὸ δωμάτιον ὑπανοίξασα Luc. Asin. 13.
intr., open underneath, ἄντρον ὑπανοίγει J. BJ 1.21.3.