The word "mobbist" is a variant spelling of the word "mobber", which is derived from the noun "mob". The word is typically used to describe a person who is involved in mobbing, or the act of bullying and harassing someone in a group. The spelling of "mobbist" follows the English orthographic conventions, where the letter "b" is pronounced as /b/ and the letter "i" as /ɪ/, resulting in the IPA transcription of /ˈmɒbɪst/.