con·di·tion 
(kən-dĭshən)
(kən-dĭshən)n.
1.
a. A mode or state of being: We bought a used boat in excellent condition. See Synonyms at state.
b. conditions Existing circumstances: Economic conditions have improved. The news reported the latest weather conditions.
c. Archaic Social position; rank.
2.
a. A state of health: Has the patient's condition deteriorated?
b. A state of physical fitness: Have you exercised enough to get back into condition?
c. A disease or physical ailment: a heart condition.
3.
a. One that is indispensable to the appearance or occurrence of another; a prerequisite: Compatibility is a condition of a successful marriage.
b. One that restricts or modifies another; a qualification: I'll make you a promise but with one condition.
4.
a. Grammar The dependent clause of a conditional sentence; protasis.
b. Logic A proposition on which another proposition depends; the antecedent of a conditional proposition.
5. Law
a. A provision making the effect of a legal instrument contingent on the occurrence of an uncertain future event.
b. The event itself.
tr.v. con·di·tioned, con·di·tion·ing, con·di·tions
1.
a. To make dependent on a condition or conditions: Use of the cabin is conditioned on your keeping it clean.
b. To stipulate as a condition: "He only conditioned that the marriage should not take place before his return" (Jane Austen).
2.
a. To cause to be in a certain condition; shape or influence: "Our modern conceptions of historiography [are] conditioned by Western intellectual traditions" (Carol Meyers).
b. To accustom (oneself or another) to something; adapt: had to condition herself to long hours of hard work; conditioned the troops to marches at high altitudes.
c. To render fit for work or use: spent weeks conditioning the old car.
d. To improve the physical fitness of (the body, for example), as through repeated sessions of strenuous physical activity.
e. Psychology To cause (an organism) to respond in a specific manner to a conditioned stimulus in the absence of an unconditioned stimulus.
3. To treat (the air in a room, for example) by air-conditioning.
4. To replace moisture or oils in (hair, for example) by use of a therapeutic product.
[Middle English condicioun, from Old French condicion, from Late Latin conditiō, conditiōn-, alteration of Latin condiciō, from condīcere, to agree : com-, com- + dīcere, to talk; see deik- in the Appendix of Indo-European roots.]