Word Study
intra-
CIDE DICTIONARY
intra-, [L. intra, prep., within, on the inside; akin to inter. See Inter-.].
A prefix signifying in, within, interior; as, intraocular, within the eyeball; intramarginal. [1913 Webster]
OXFORD DICTIONARY
intra-, prefix forming adjectives usu. from adjectives, meaning 'on the inside, within' (intramural).
Etymology
L intra inside
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