pro·trac·tor 
(prō-trăktər, prə-)
(prō-trăktər, prə-)n.
1. A semicircular instrument for measuring and constructing angles.
2. Anatomy A muscle that extends a limb or other part.
- photolytically
- photomap
- photomechanical
- photomechanically
- photometer
- photometric
- photometrical
- photometrically
- photometric brightness
- photometrist
- photometry
- photomicrograph
- photomicrographer
- photomicrographic
- photomicrography
- photomicroscope
- photomicroscopic
- photomontage
- photomultiplier
- photomural
- photomuralist
- photon
- photonegative
- photonic
- photonics