'atonalistic' originates from English, specifically from the adjective 'atonal' combined with the adjectival suffix '-istic'. 'Atonal' itself is formed from the prefix 'a-' meaning 'not' and 'tonal' (from 'tone'), where 'tone' comes from Latin 'tonus' and Greek 'tonos' meaning 'stretching' or 'pitch'.

'Atonal' was coined in the early 20th century (around the 1910s–1920s) to describe music without a tonal center; adding the suffix '-istic' (a later English adjectival formation) produced 'atonalistic' as a descriptive variant in English usage.

Initially the element meant 'not tonal' (i.e., lacking a key or tonal center); over time it has come to denote characteristics associated with atonality or the atonal movement in modern music (i.e., 'relating to atonal music').