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