Meaning

• To change with time or a similar parameter.

  "He varies his magic tricks so as to minimize the possibility that any given audience member will see the same trick twice."

• To institute a change in, from a current state; to modify.

  "You should vary your diet. Eating just bread will do you harm in the end."

• Not to remain constant: to change with time or a similar parameter.

  "His mood varies by the hour."

• (of the members of a group) To display differences.

  "The sprouting tendency of potatoes varies between cultivars, years and places of growing."

• To be or act different from the usual.

• To make of different kinds; to make different from one another; to diversity; to variegate.

• To embellish; to change fancifully; to present under new aspects, as of form, key, measure, etc. See variation.

• To disagree; to be at variance or in dissension.

Meaning

• A kind of variable, used by a fragment shader, that interpolates values across a primitive, so as to produce gradient effects etc.