形容詞 obsolescent:

1. becoming obsolete

ob.so.les.cent

adj.（形容詞）
Being in the process of passing out of use or usefulness; becoming obsolete.
逐漸廢棄不用的：正處于廢退或無用的過程；正成為廢品的
Biology Gradually disappearing; imperfectly or only slightly developed. Used of an organ or other part of an animal or a plant.
【生物學(xué)】 退化的：逐漸消亡的；沒有完全退化或進(jìn)化程度微小的。用于指動(dòng)物或植物的器官或其它部分

來源：
Latin obsolôscôns obsolôscent- [present participle of] obsolôscere [to fall into disuse]
拉丁語 obsolôscôns obsolôscent- [] obsolôscere的現(xiàn)在分詞 [成為廢止不用的狀態(tài)]
ob- [away] * see ob-
ob- [離開] *參見 ob-
solôre [to be accustomed to]
solôre [習(xí)慣于]

【引伸】
ob.soles.cence
n.（名詞）
ob.soles.cently
adv.（副詞）