'even-jawed' is a modern English compound formed from 'even' + the adjectival form of 'jaw' ('jawed'), meaning literally 'having even jaws'.

The element 'even' originates from Old English 'efen' ('equal, level'), while 'jaw' comes from Old English ('ceafl') meaning 'jaw, cheek, jawbone'. The compound formation 'even-jawed' follows a productive pattern in Modern English of combining an adjective with '-ed' to describe a physical quality.

Originally a literal descriptive term for jaw alignment ('having jaws of equal form'), it has also been used figuratively to describe generally balanced or harmonious facial features.