Word Study
Extra-
CIDE DICTIONARY
Extra-, [L., fr. exter. See Exterior.].
A Latin preposition, denoting beyond , outside of ; -- often used in composition as a prefix signifying outside of , beyond , besides , or in addition to what is denoted by the word to which it is prefixed. [1913 Webster]
OXFORD DICTIONARY
Extra-, comb. form 1 outside, beyond (extragalactic).
2 beyond the scope of (extracurricular).
2 beyond the scope of (extracurricular).
Etymology
med.L f. L extra outside
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