critical period

15 LETTERS · STARTS WITH C

critical period is a valid 15-letter word worth 21 points in Scrabble and 25 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
C3R1I1T1I1C3A1L1P3E1R1I1O1D2
3 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 1 + 2 =21 PTS
DOUBLE WORD → 42TRIPLE WORD → 63
MEANING

What does critical period mean?

1