pro·to·his·to·ry 
(prō′tō-hĭstə-rē, -hĭstrē)
(prō′tō-hĭstə-rē, -hĭstrē)n.
The study of a culture just before the time of its earliest recorded history.
pro′to·his·tori·an (-hĭ-stôrē-ən, -stŏr-) n.
pro′to·his·toric (-hĭ-stôrĭk, -stŏr-) adj.
- keep company
- keep down
- keep end up
- keeper
- keep eyes open
- keep eyes peeled
- keep fingers crossed
- keep head
- keep/hold (one's) peace
- keeping
- keep/know (one's) place
- keep kosher
- keep nose clean
- keep nose to the grindstone
- keep off
- keep (one's) chin up
- keep one's chin up
- keep one's end up
- keep one's eyes open
- keep (one's) eyes open/peeled
- keep one's eyes peeled
- keep one's fingers crossed
- keep (one's) head
- keep one's head
- keep (one's) nose clean