名詞 ratite:

1. flightless birds having flat breastbones lacking a keel for attachment of flight muscles: ostriches; cassowaries; emus; moas; rheas; kiwis; elephant birds
   同義詞：ratite bird, flightless bird

rat.ite

adj.（形容詞）
Relating to or being any of a group of flightless birds having a flat breastbone without the keellike prominence characteristic of most flying birds.
平胸鳥的：與一種平胸，沒有一般飛翔性鳥類所特有的龍骨狀突起的不會飛的鳥有關的；屬于這一類鳥的
n.（名詞）
A ratite bird, such as the ostrich or emu.
平胸鳥：平胸鳥，如鴕鳥和鶴鴕

來源：
From Latin ratotus [marked with the figure of a raft]
源自 拉丁語 ratotus [具有浮排形特征的]
from ratis [raft]
源自 ratis [浮排]