名詞 posterior:

1. the fleshy part of the human body that you sit on
   同義詞：buttocks, nates, arse, butt, backside, bum, buns, can, fundament, hindquarters, hind end, keister, prat, rear, rear end, rump, stern, seat, tail, tail end, tooshie, tush, bottom, behind, derriere, fanny, ass
2. a tooth situated at the back of the mouth
   同義詞：back tooth

形容詞 posterior:

1. at or near the hind end in quadrupeds or toward the spine in primates

1. The condition of being posterior in location or time.
   在后在位置上或時(shí)間上較靠后的狀況
2. A fixture similar in design to a toilet that is straddled for bathing the genitals and the posterior parts.
   清洗盆一種在設(shè)計(jì)上像便池的固定裝置，可叉開腿跨坐于上洗浴生殖器和臀部
3. Located or occurring posterior to the nose.
   鼻后的位于鼻后的，或發(fā)生于鼻后的
4. It is a posterior view of the skull.
   這是顱骨背視圖。

pos.te.ri.or

adj.（形容詞）
Located behind a part or toward the rear of a structure.
后部的，后面的：位于某部分之后的，在結(jié)構(gòu)之尾部的
Relating to the caudal end of the body in quadrupeds or the dorsal side in human beings and other primates.
背后的，尾部的：與四足獸的身體尾部有關(guān)的，或與人類和其他靈長動(dòng)物的背部有關(guān)的
Botany Next to or facing the main stem or axis.
【植物學(xué)】 近莖軸一側(cè)的：緊挨著主莖或軸的，面向主莖或軸的
Coming after in order; following.
在后的，其次的：次序上較后的；相繼的
Following in time; subsequent.
隨后的，后來的：時(shí)間上較后的；隨后的
n.（名詞）
The buttocks.
屁股

來源：
Latin [comparative of] posterus [coming after]
拉丁語 [] posterus的比較級(jí) [隨后來的]
from post [afterward] * see apo-
源自 post [朝后] *參見 apo-

【引伸】
poste.riorly
adv.（副詞）