Origin: Latin suffix -ary
Contrary has 11 different meanings across 2 categories:
a logical relation such that two propositions are contraries if both cannot be true but both can be false
"In the square of opposition, the statements "All swans are white" and "No swans are white" stand as contraries because they cannot both be true simultaneously yet could both be false if some swans were white."
The opposite.
"The weather turned out to be contrary to our expectations, bringing rain instead of sunshine."
To oppose; to frustrate.
"The strong wind was contrary to our sailing plans, forcing us to turn back immediately."
very opposed in nature or character or purpose
"acts contrary to our code of ethics"
"the facts point to a contrary conclusion"
of words or propositions so related that both cannot be true but both may be false
"`hot' and `cold' are contrary terms"
Opposite; in an opposite direction; in opposition; adverse.
"The wind was contrary to our sailing plans, pushing us directly away from the harbor."
In plain English: Contrary means being completely opposite to what is expected or true.
"Her contrary nature often led her to do exactly what everyone else told her not to do."
Usage: Use contrary to describe something that opposes or is the reverse of another idea, such as weather conditions going contrary to expectations. Do not confuse this with contrariwise, which functions more like a transition word meaning "on the other hand."
Contrarily
"He acted contrary to his usual nature by staying home instead of going out."
The word entered English via the French as "contrary," tracing its roots back to a Latin term meaning "opposed" or set against something. Originally derived from a phrase literally translating to "standing opposite," it has retained this sense of opposition throughout its history in the language.