noun
arbitrariness; self-will; whim
Refers to acting based on one's own desires or whims without regard for rules or others' opinions. Often used in formal or critical contexts.
彼の決定は恣意的だ。
His decision is arbitrary.
恣意に流されず、公正な判断を下すべきだ。
You should make a fair judgment without being swayed by self-will.
From Middle Chinese-derived kanji 恣 (selfish, arbitrary) and 意 (mind, intention). The exact historical derivation is uncertain, but the compound has been used in formal Japanese to denote self-willed or arbitrary behavior.