'antimotility' originates from English formation using the prefix 'anti-' (from Greek 'anti-' meaning 'against') combined with 'motility' (from Latin root 'motus' meaning 'movement' plus suffix '-ity').

'motility' derived from Latin 'motilitas' (from 'motus' meaning 'movement') via Medieval/Modern Latin into English as 'motility'; the prefix 'anti-' (Greek) was attached in Modern English to form the compound 'antimotility', particularly in 20th century medical usage.

Initially the components literally meant 'against movement'; over time the compound came to denote specifically the inhibition of bodily movement (most commonly intestinal movement) or drugs that cause such inhibition.