over-

1. a prefixal use of over, preposition, adverb, or adjective, occurring in various senses in compounds (overboard; overcoat; overhang; overlap; overlord; overrun; overthrow), and especially employed, with the sense of “over the limit,” “to excess,” “too much,” “too,” to form verbs, adjectives, adverbs, and nouns (overact; overcapitalize; overcrowd; overfull; overmuch; oversupply; overweight), and many others, mostly self-explanatory: a hyphen, which is commonly absent from old or well-established formations, is sometimes used in new coinages or in any words whose component parts it may be desirable to set off distinctly.

prefix

1. excessive or excessively; beyond an agreed or desirable limitovercharge; overdue; oversimplify
2. indicating superior rankoverseer
3. indicating location or movement aboveoverhang
4. indicating movement downwardsoverthrow

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, though this is rare in Modern English. Cf. Gothic ufarmunnon “to forget,” ufar-swaran “to swear falsely;” Old English ofercræft “fraud.”