MERER is a playable word

mere Scrabble® Dictionary

adjective
merer, merest
being nothing more than
(adverb) merely
noun
pl. meres
a pond or lake
11 Playable Words can be made from "MERER"
   2-Letter Words (4 found)
   3-Letter Words (5 found)
   4-Letter Words (1 found)
   5-Letter Words (1 found)