noun
appropriate response; expedient action
Refers to acting flexibly and appropriately according to changing circumstances. Most commonly encountered in the set phrase 臨機応変 (りんきおうへん), meaning 'adapting to the situation' or 'playing it by ear'. As a standalone noun, usage is somewhat limited and often formal or written.
この仕事では臨機応変な対応が求められる。
This job requires the ability to respond flexibly to changing circumstances.
応変の処置を取る必要がある。
We need to take appropriate measures according to the situation.
Compound of 応 (おう, 'respond') and 変 (へん, 'change'), literally meaning 'responding to change'. The exact historical derivation is uncertain, but it is a Sino-Japanese word (kango) that became established through classical Chinese influence.