SOUR is a playable word

sour Scrabble® Dictionary

adjective
sourer, sourest
sharp or biting to the taste
verb
soured, souring, sours
to make or become sour
9 Playable Words can be made from "SOUR"
   2-Letter Words (4 found)
   3-Letter Words (3 found)
   4-Letter Words (2 found)