An adverb expressing indifference or that something does not matter (commonly used in phrases like 'どうでもいい' or 'どうでもかまわない').
結果はどうでもいい。やるだけやろう。
The result doesn't matter. Let's just do it.
彼の意見はどうでも気にしない。
I don't care about his opinion.
色はどうでも構わないから、サイズを教えてください。
I don't care about the color — just tell me the size.
A rarer usage meaning 'by all means' or 'no matter what it takes.' In modern Japanese, この意味 is usually expressed with 'どうしても'; this sense is limited or somewhat old-fashioned.
（稀）彼はどうでもこの任務を成し遂げようとした。
(rare) He tried to accomplish this mission no matter what.
（稀）どうでも間に合わせてほしいと言われた。
(rare) He was told to get it done by any means.