'antinodal' originates from the prefix 'anti-' (from Greek 'anti-', meaning 'against, opposite') combined with 'nodal' (from 'node' + adjectival suffix '-al'), where 'node' traces to Latin 'nodus' meaning 'knot'.

'antinodal' was formed in modern English by combining 'anti-' with 'nodal' (late 19th to early 20th century usage in physics). 'Nodal' itself comes from English 'node' (Middle English), from Latin 'nodus'.

Initially formed to mean 'opposite or relating to a node'; in physics it has come to mean specifically 'located at or relating to an antinode (the point of maximum amplitude in a standing wave)'.