against
a-gainst
preposition
Contrary to, in violation of, or in disagreement with.
"It's against the law."
preposition
In opposition to, conflicting with, or competing with.
"We played against the local team."
preposition
To the disadvantage or detriment of someone or something.
"The odds are against us."
preposition
In physical contact with or leaning on something for support.
"He leant against the wall."