'symmetrical-jawed' originates in Modern English as a compound of 'symmetrical' and 'jaw'. 'symmetrical' ultimately traces back to Greek, specifically the word 'symmetria', where the root 'sym-' meant 'together' and 'metria' meant 'measure'. 'jaw' comes from Old English (via Middle English) the word 'ceaf'/'jawe', meaning 'jaw' or 'cheek'.

'symmetrical' passed into English via Latin/Medieval Latin and Old French from Greek 'symmetria', becoming the Modern English 'symmetrical'; 'jaw' evolved from Old English 'ceaf' to Middle English 'jawe' and then to Modern English 'jaw'. The compound form 'symmetrical-jawed' is a modern English descriptive formation.

Initially, components meant 'agreement in measure' (for 'symmetrical') and 'jaw/cheek' (for 'jaw'); over time the compound came to mean 'having jaws that are symmetrical' in modern descriptive usage.