To express disapproval of something. The teacher deprecated the student's lack of effort in completing the assignment.
To belittle or make something seem less important. He deprecated his own achievements, insisting that anyone could have done the same.
In software, to mark a feature or function as obsolete and recommend against its use, often because it will be removed in the future. The developer deprecated the old API in favor of a more efficient version.
Archaic: To seek to avert or ward off (something undesirable) by prayer or earnest entreaty. The villagers held a ceremony to deprecate any further misfortune.