A.T. Robertson Commentary Luke 1:24

"And after these days Elisabeth his wife conceived; and she hid herself five months, saying," — Luke 1:24 (ASV)

Conceived (συνελαβεν). Luke uses this word eleven times and it occurs only five other times in the N.T. It is a very old and common Greek word. He alone in the N.T. has it for conceiving offspring (1:24,31,36; 2:21) though Jas 1:15 uses it of lust producing sin. Hobart (Medical Language of Luke, p. 91) observes that Luke has almost as many words for pregnancy and barrenness as Hippocrates (εν γαστρ εχειν, 21:23; εγκυος, 2:5; στειρα, 1:7; ατεκνος, 20:28).

Hid (περιεκρυβεν). Only here in the N.T., but in late Koine writers. Usually considered second aorist active indicative from περικρυπτω, though it may be the imperfect indicative of a late form περικρυβω. If it is aorist it is the constative aorist. The preposition περ makes it mean completely (on all sides) hid.