Definitions for over-

Random House Webster's College Dictionary

o•verˈoʊ vər(prep.)

above in place or position:
the roof over one's head.
above and to the other side of:
to leap over a wall.
above in authority, rank, power, etc.:
no one over her in the department.
so as to rest on or cover; on or upon:
Throw a sheet over the bed.
on top of:
to hit someone over the head.
here and there on or in; about:
at various places over the country.
through all parts of; all through:
to show someone over the house.
to and fro on or in; across; throughout:
to travel over Europe.
from one side to the other of; to the other side of; across:
to go over a bridge.
on the other side of; across:
lands over the sea.
reaching higher than, so as to submerge:
The water is over his shoulders.
in excess of; more than:
not over five dollars.
above in degree, quantity, etc.:
a big improvement over last year's turnout.
in preference to:
chosen over another applicant.
throughout the length or duration of:
The message was sent over a great distance; over a long period of years.
until after the end of:
to adjourn over the holidays.
in reference to, concerning, or about:
to quarrel over a matter.
while doing or attending to:
to fall asleep over one's work.
via; by means of:
I heard it over the radio.
Category: Radio and Television
(adv.)beyond the top or upper part of something:
a roof that hangs over.
so as to cover or affect the whole surface:
The furniture was covered over with dust.
through a region, area, etc.:
known the world over.
at some distance, as in a direction indicated:
They live over by the hill.
from one side or place to another or across an intervening space:
to sail over; Toss the ball over, will you? Let's walk over to the coffee shop.
across or beyond an edge or rim:
The soup boiled over.
Category: Common Vocabulary
from beginning to end; throughout:
Think it over.
from one person, party, etc., to another:
He made the property over to his brother.
on the other side, as of a sea, a river, or any space:
over in Japan.
so as to displace from an upright position:
to knock over a glass.
so as to put or be in the reversed position:
The dog rolled over.
once more; again:
Do the work over.
in repetition or succession:
20 times over.
in excess or addition:
to pay the full sum and something over.
in excess of or beyond a certain amount:
Five goes into seven once, with two over.
throughout or beyond a period of time:
to stay over till Monday.
(adj.)upper; higher up.
higher in authority, station, etc.
serving or intended as an outer covering; outer (often used in combination):
a gown with an overskirt.
remaining or additional, surplus; extra.
too great; excessive (usu. used in combination):
overaggressive behavior.
ended; done; past:
when the war was over.
(n.)an amount in excess or addition; extra.
a shot that strikes or bursts beyond the target.
Category: Military
Cricket. the number of balls, usu. six, delivered between successive changes of bowlers. the part of the game played between such changes.
Category: Sport
(v.t.)to go or get over; leap over.
(interj.)(used in radio communications to signify that the sender is awaiting a reply to or acknowledgment of a transmission.)
Category: Common Vocabulary, Radio and Television

Idioms for over:

all over, ended; finished; over with: throughout; everywhere:
The game is all over.
all over the place.
Category: Idiom
over and above,in addition to; besides.
Category: Idiom
over and over,many times; repeatedly.
Category: Idiom
over the hill,past one's prime.
Category: Idiom
over with,finished; ended; done.
Category: Idiom

Origin of over:

bef. 900; ME; OE ofer; c. OFris ovir, OHG ubar(i), ON yfir; akin to L super, Gk hypér, Skt upari. See up, hyper-

over-

a prefixal use of over , occurring in various senses in compounds (overboard; overcoat; overhang; overlord; overthrow), and esp. employed, with the senses “over the limit,”“to excess,”“too much,”“too,” to form verbs, adjectives, adverbs, and nouns (overact; overcrowd; overfull; overweight).
Category: Affix