To allow the existence, occurrence, or practice of something that one does not necessarily like or agree with, without interference. The teacher tolerated the students' chatter during the break.
To endure or resist the action of a drug, poison, or other substance without adverse effects. Some people can tolerate higher doses of medication than others.
To withstand or endure (an environmental or physical condition) without serious adverse effect. Desert plants can tolerate prolonged periods of drought.