'Apollinarist' originates from Late Latin/Medieval Latin, specifically the name 'Apollinaris' (the name of the 4th-century bishop Apollinaris of Laodicea), with the English suffix '-ist' meaning 'one who follows or supports'. The personal name 'Apollinaris' itself derives ultimately from the Greek name related to 'Apollo' (meaning 'of Apollo' or 'belonging to Apollo').

'Apollinaris' (a proper name in Late Latin, from Greek) was used to describe the bishop and his followers; Medieval Latin/Church Latin forms such as 'Apollinarista' or similar were employed for adherents, and English borrowed the form and added the productive English suffix '-ist' to form 'Apollinarist'.

Initially the term simply identified something or someone 'of or belonging to Apollinaris' (i.e., connected to the person); over time it came to be used specifically for an adherent of the theological position (Apollinarism) and for things relating to that doctrine.