Welsh grug

← Proto-Brythonic *gwrʉg (inherited)

← Proto-Celtic *wroikos (inherited)

← Czech vřes (cognate)

← Ancient Greek ἐρείκη (cognate)

← Latvian virsis (cognate)

← Middle Welsh gwrug (inherited)

→ English grig (derived)

→ Welsh gruga (affix)

→ Spanish brezo (cognate)

→ Irish fraoch (cognate)

→ Galician breixo (cognate)

→ Alemannic German Brüüsch (cognate)