One of these is ikigao ( イキガオ) meaning 'coming face'. There are several other names for the facial expressions made at the moment of orgasm. Thus, ahegao can be interpreted as 'moaning or panting face.'
The second part, gao or kao ( 顔) means 'face'. The first part of the term, ahe ( katakana: アヘ) is an abbreviation for aheahe ( アヘアヘ), an onomatopoeia for 'pant' or 'moan'.