素
1
one's nature;one's feelings;oneself
どうやら、さっきのは演技ではなく、素だったらしい。
It seems like that she wasn't acting back then; they were her real feelings.
2
plain;unadorned;undecorated;unadulterated;au naturel
3
prefix
mere;poor
before a noun
4
prefix
exceedingly
before an adjective