He has a cowardly personality and doesn't dare resist.
Tips
mistakes
懦弱 describes a deeply ingrained personality trait - chronic timidity. For situational fear, use 害怕 (scared) or 胆小 (timid). 懦弱 is harsher and more judgmental.
memory
Both characters share the 'heart' radical (忄/心), because cowardice is a matter of the heart. 懦 = weak-hearted, 弱 = weak.
