Refers to a person's past actions or conduct, often with a moral or evaluative nuance. Somewhat formal and less common in everyday speech than 行動 or 振る舞い.
We need to investigate his past conduct.
There is room for doubt about that politician's behavior.
misconduct; impropriety; profligacy
Compound of 行 (action, conduct) and 跡 (trace, mark), literally 'traces of actions'. The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning of past deeds or behavior.