in opposition to; contrary to; adverse or hostile to:
twenty votes against ten; against reason.
2.
in resistance to or defense from:
protection against burglars.
3.
in an opposite direction to:
to ride against the wind.
4.
into contact or collision with; toward; upon:
The rain beat against the window.
5.
in contact with:
to lean against the wall.
6.
in preparation for; in provision for:
money saved against a rainy day.
7.
having as background:
a design of flowers against a dark wall.
8.
in exchange for; as a balance to or debit or charge on:
He asked for an advance against his salary.
9.
in competition with:
a racehorse running against his own record time.
10.
in comparison or contrast with:
a matter of reason as against emotion.
11.
beside; near; before:
The car is against the building.
conjunction
12.
Archaic. before; by the time that.
Idioms
13.
over against, in contrast with:
the rich over against the poor.
Origin
1125-75;Middle Englishagens, ageynes, equivalent to ageynagain + -es-s1; for -t cf. whilst, amongst
Examples from the web for against
During the past twelve months many major currencies have risen against the dollar.
They are held against their will and forced to work without pay.
The antibody binding site, tucked away in a stable region of the virus, might form the first lasting vaccine against flu.
Of course, this whole thing has been a race against time.
Hand pulling or hoeing is your first line of defense against weeds, especially annual and biennial kinds.
And attempts to use private security-backed militias as proxies against pirates haven't produced much results, either.
Most major currencies have weakened against the dollar since the end of last year.
The toads make the toxins to protect themselves against predators, which learn not to eat the deadly amphibians.
These all against us, and the job on our hands is too large for us.
Learn how to grow it against a wall or up an arbor.
British Dictionary definitions for against
against
/əˈɡɛnst; əˈɡeɪnst/
preposition
1.
opposed to; in conflict or disagreement with: they fought against the legislation
2.
standing or leaning beside or in front of: a ladder against the wall
3.
coming in contact with: the branches of a tree brushed against the bus
4.
in contrast to: silhouettes are outlines against a light background
5.
having an adverse or unfavourable effect on: the economic system works against small independent companies
6.
as a protection from or means of defence from the adverse effects of: a safeguard against contaminated water
7.
in exchange for or in return for
8.
(rare) in preparation for: he gave them warm clothing against their journey through the night
9.
as against, as opposed to or as compared with: he had two shots at him this time as against only one last time
Word Origin
C12: ageines, from again, ageyn, etc, again + -es genitive ending; the spelling with -t (C16) was probably due to confusion with superlatives ending in -st
Word Origin and History for against
adv.
early 12c., agenes "in opposition to," a southern variant of agen "again" (see again), with adverbial genitive. The parasitic -t turned up mid-14c. and was standard by early 16c., perhaps from influence of superlatives.