Yes, VARIANCES is a Scrabble word!

Letter values in Scrabble US: V 4, A 1, R 1, I 1, A 1, N 1, C 3, E 1, S 1.

Is it a valid word?

VARIANCES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

an event that departs from expectations
discord that splits a group
the second moment around the mean; the expected value of the square of the deviations of a random variable from its mean value
a difference between conflicting facts or claims or opinions
the quality of being subject to variation
an official dispensation to act contrary to a rule or regulation (typically a building regulation)
an activity that varies from a norm or standard