Longman Dictionary of Contemporary English
over-
prefix
EXAMPLES FROM OTHER ENTRIES
▪ an overcrowded room
Douglas Harper's Etymology Dictionary
over-
word-forming element meaning "above; highest; across; too much; above normal; outer," from Old English ofer (see over). Over and its Germanic relations were widely used as prefixes, and sometimes could be used with negative force. This is rare in Modern English, but compare Gothic ufarmunnon "to forget," ufar-swaran "to swear falsely;" Old English ofercræft "fraud."
Wiktionary
over-
pre. 1 above, or higher 2 superior 3 excessively 4 surrounding or covering