From pros and meno; to stay further, i.e. Remain in a place, with a person; figuratively, to adhere to, persevere in -- abide still, be with, cleave unto, continue in (with).
see GREEK pros
see GREEK meno
a. to remain with (see πρός, IV. 3): with a dative of the person to continue with one, Matthew 15:32; Mark 8:2 (here L WH marginal reading omit; Tr brackets the dative); τῷ κυρίῳ, to be steadfastly devoted to (A. V. cleave unto) the Lord, Acts 11:23 (Wis. 3:9; Josephus, Antiquities 14, 2, 1); τῇ χάριτι τοῦ Θεοῦ, to hold fast to (A. V. continue in) the grace of God received in the gospel, Acts 13:43 G L T Tr WH; δεήσεσι καί προσευχαῖς (A. V. to continue in supplications and prayers), 1 Timothy 5:5.
b. to remain still (cf. πρός, IV. 2), stay, tarry: Acts 18:18; followed by ἐν with a dative of place, 1 Timothy 1:3.