Lacking strength or vigor; weak or feeble (of body, voice, movement, etc.).
高齢のため、彼の歩き方は最近力弱くなった。
Because of his age, his way of walking has become weak recently.
発表中、緊張して声が力弱く聞こえた。
During the presentation, his voice sounded weak from nervousness.
病み上がりで腕がまだ力弱い。
After recovering from illness, his arms are still weak.