IPA: /ˌdɛprɪˈkeɪʃən/
KK: /dɛprɪˈkeɪʃən/
The act of expressing disapproval or criticism of something, often with the hope of preventing it from happening.
The software update included a deprecation of the old features that users had relied on.
Deprecation is formed from "de-" (meaning down or away) and "precari" (meaning to pray or to entreat). The word refers to the act of expressing disapproval or a wish for something to be removed or diminished, as if one is praying against it.
Think of 'praying down' or 'away' from something undesirable — that's why deprecation means expressing disapproval or wishing for something to be lessened.