STEP Greek Lexicon: ὑποκάτω

ύπο-κάτω comp. adv. (see M, Pr., 99),

[in LXX chiefly for תַּחַת ;]

below, under: as prep. with genitive, Mat.22:44, Mrk.6:11 7:28 12:36 (Rec., R, txt., ὑποπόδιον, as in LXX), Luk.8:16, Jhn.1:51, Heb.2:8" (LXX), Rev.5:3, 13 6:9 12:1.†

(AS)