Noun

1. The prevailing context that influences the performance or the outcome of a process
2. The set of circumstances that affect someone's welfare
3. The atmospheric conditions that comprise the state of the atmosphere in terms of temperature and wind and clouds and precipitation
4. A state at a particular time
5. An assumption on which rests the validity or effect of something else
6. A mode of being or form of existence of a person or thing
7. Information that should be kept in mind when making a decision
8. The state of (good) health (especially in the phrases `in condition' or `in shape' or `out of condition' or `out of shape')
9. An illness, disease, or other medical problem
10. (usually plural) a statement of what is required as part of an agreement
11. The procedure that is varied in order to estimate a variable's effect by comparison with a control condition

Verb

1. Establish a conditioned response
2. Develop (children's) behavior by instruction and practice; especially to teach self-control
3. Specify as a condition or requirement in a contract or agreement; make an express demand or provision in an agreement
4. Put into a better state
5. Apply conditioner to in order to make smooth and shiny