undersized

形容词 undersized:

1. smaller than normal for its kind
   同义词：undersize

1. Although he seemed thin and undersized compared with his cousins, he was really as hard as nails and didn't fall ill half as often as they did.
   和堂兄弟们相比，他看上去好像又瘦又矮小，实际上他身体好像又瘦又矮小，实际上他身体非常强壮，生病的次数比他们少多了。