IPA: //ʌnˈhætɪŋ//
KK: /ʌnˈhætɪŋ/
The act of removing a hat, often done as a sign of respect or politeness, such as when greeting someone or during a formal occasion.
He performed an unhatting as he entered the room to show respect to the guests.
Unhatting is formed from "un-" (meaning not or opposite of) and "hat" (from Old English "hæt", meaning a head covering) and the suffix "-ing" (indicating the action or process of). The word refers to the action of removing a hat or the process of taking off a head covering.
Think of 'un-' meaning not or opposite, and 'hat' as a head covering — so unhatting means the action of taking off a hat.