expression, adverb
by any means; at all costs; no matter what
Expresses strong determination to achieve something regardless of obstacles, right or wrong, or consequences. Often used with volitional or imperative expressions.
是が非でも明日までにこの仕事を終わらせなければならない。
I must finish this work by tomorrow, no matter what.
彼は是が非でもその計
He tried to carry out the plan by any means possible.
A fixed expression combining 是 (right) and 非 (wrong) with the particle でも, literally meaning 'even if it is right or wrong', i.e., regardless of the means or consequences.