Meanings

1. adverbin any case; regardless; either way; after all; no matter what; anywayindicates inevitability of outcome, resignation or scorn
2. adverbsince it makes no difference anyway (you might as well ...); since it won't change the outcome; if you are doing it regardlessfollowed by a conditional, or as ～...だから

Examples

• どうせお前は。

  You're only foolin' round.

• どうせ行くんでしょ。

  I daresay you are going to go no matter what.

• どうせやるなら上手にやれ。

  If you do it at all, do it well.

Sentences from Tatoeba (CC BY 2.0 FR).