名詞 extra-:

1. a minor actor in crowd scenes
   同義詞：supernumerary, spear carrier, extra
2. an additional edition of a newspaper (usually to report a crisis)
   同義詞：extra
3. something additional of the same kind
   同義詞：extra, duplicate

形容詞 extra-:

1. more than is needed, desired, or required
   同義詞：excess, extra, redundant, spare, supererogatory, superfluous, supernumerary, surplus
2. added to a regular schedule
   同義詞：extra, special
3. further or added
   同義詞：extra, additional

副詞 extra-:

1. unusually or exceptionally
   同義詞：extra

extra- 或 extro-
pref.（前綴）
Outside; beyond:
在…之外，超出：
例句：
extraterritorial.
地球外的

來(lái)源：
Late Latin
后期拉丁語(yǔ)
from Latin extr3 * see eghs
源自 拉丁語(yǔ) extr3 *參見(jiàn) eghs