1. be sth. you can understand or explain能理解;合理
What he said just doesn't make sense. 他講的那番話簡直不知所雲。
She doesn't talk much, but what she says makes sense. 她不多講話,但言之有理。
2. seem right; sound reasonable or practical可行;合乎情理
Does it make sense to let little children play with matches?讓孩子們玩火柴能行嗎?