1: capacity to endure pain or hardship :endurance, fortitude, stamina 2 a: sympathy or indulgence for beliefs or practices differing from or conflicting with one's own b: the act of allowing something :toleration 3: the allowable deviation from a standard; especially: the range of variation permitted in maintaining a specified dimension in machining a piece 4 a (1): the capacity of the body to endure or become less responsive to a substance (as a drug) or a physiological insult especially with repeated use or exposure <developed a tolerance to painkillers>; also: the immunological state marked by unresponsiveness to a specific antigen (2): relative capacity of an organism to grow or thrive when subjected to an unfavorable environmental factor b: the maximum amount of a pesticide residue that may lawfully remain on or in food
