Where does “αθυρόστομος” come from?

αθυρόστομος (Greek) comes from Greek στόμα, from Ancient Greek στόμα, from Proto-Indo-European stomn̥.

αθυρόστομος (Greek): foul-mouthed, profane; impertinent, garrulous,...

Definitions

αθυρόστομος traces back through two separate lines of ancestry.

Step	Language	Word	Meaning
1	Greek	στόμα	mouth; person
2	Ancient Greek	στόμα	mouth; face; The source of a river or stream
3	Proto-Indo-European	stomn̥	—

Step	Language	Word	Meaning
1	Greek	θύρα	door; a gate in a stadium; a PC port
2	Ancient Greek	θύρα	door; entrance
3	Proto-Hellenic	*tʰurā	—