1 behaving as a mother would behave; connected with being a mother 母亲的；母亲般的: maternal love/instincts 母爱；母亲的本能

2 (only before a noun 只用于名词前) related through your mother's side of the family 母系的；母亲一方的: your maternal grandfather 你的外祖父 ☞ Look at paternal. 参看paternal。