Complementary for \$SAT\$

I have tried to find a definition of complementary language to $$SAT$$, I mean $$overline{SAT}$$.
But I still confused, in case of $$Lin overline{SAT}$$ is it mean:
if $$varphiin L$$ then all interpretations are satisfy and
if $$varphinotin L$$ then exists interpretation that unsatisfy
OR vice versa
if $$varphinotin L$$ then all interpretations are satisfy and
if $$varphiin L$$ then exists interpretation that unsatisfy

please if you downvote write explanation of why