Proto-Germanic *-þrą, from Proto-Indo-European *-trom.
- Instrumental suffix creating neuter nouns from verbs
- rōþor "instrument used for rowing, rudder"
- heaþor "restraint, confinement", from hæf, a derivative of hafenian "to hold, grasp"
- Suffix used to denote the agent or means by which an action is performed
- lēaþor "washing agent, soap, lather"
- ġealdor "magic charm, incantation, spell"
Declension of -þor (strong a-stem)