WordReference Random House Unabridged Dictionary of American English © 2025
po•si•tion•er
(pə zish′ə nər),USA pronunciation n.
- Dentistrya person or thing that positions.
- Dentistry[Orthodontics.]a removable device of resilient plastic material worn in the mouth usually during sleep to produce minor adjustments in the position of teeth after straightening appliances have been taken off.
- position + -er1 1930–35