Deprecate - to think little of, to disapprove of.

In programming stuff that's deprecated is something no longer officially supported, because it's been replaced by something newer. For example, the FONT tag is deprecated in HTML 4.

My guess is the shift in meaning of this word (compared to Webster 1913's definition) is probably related to its closeness to depreciate.

Dep"re*cate (?), v. t. [imp. & p. p. Deprecated (?); p. pr. & vb. n. Deprecating (?).] [L. deprecatus, p. p. of deprecari to avert by player, to deprecate; de- + precari to pray. See Pray.]

To pray against, as an evil; to seek to avert by player; to desire the removal of; to seek deliverance from; to express deep regret for; to disapprove of strongly.

His purpose was deprecated by all round him, and he was with difficulty induced to adandon it. Sir W. Scott.

© Webster 1913.