名詞 ordovician:

1. from 500 million to 425 million years ago; conodonts and ostracods and algae and seaweeds
   同義詞：Ordovician period

Or.do.vi.cian

adj.（形容詞）
Of, relating to, or designating the geologic time, system of rocks, and sedimentary deposits of the second period of the Paleozoic Era, characterized by the appearance of primitive fishes.See table at geologic time
奧陶紀(jì)（系）的：屬于、有關(guān)或指奧陶紀(jì)（系）的，奧陶紀(jì)（系）是指古生代第二紀(jì)的一段地質(zhì)時間、巖石系統(tǒng)及沉積物，該紀(jì)以早期魚的出現(xiàn)為特征參見 geologic time
n.（名詞）
The Ordovician Period.
奧陶紀(jì)

來源：
From Latin Ordovicôs [an ancient Celtic tribe of Wales]
源自 拉丁語 Ordovicôs [古代威爾士的凱爾特部落]
from Celtic Ordovices * see weik- 3
源自 凱爾特語 Ordovices *參見 weik- 3