←
Proto-Hellenic *tséhō (inherited)
←
Proto-Indo-European (inherited)
←
Proto-Indo-European *tweys- (mention)
→
Spanish sismo (mention)
→
Ancient Greek Σεμέλη (affix)
→
Ancient Greek σεῖσμα (mention)
→
Ancient Greek σείσων (mention)
→
Portuguese sismo (mention)