ex·ten·si·ty 
(ĭk-stĕnsĭ-tē)
(ĭk-stĕnsĭ-tē)n. pl. ex·ten·si·ties
1.
a. The quality of having extension or being extensive.
b. A specific degree or range of extension.
2. The attribute of sensation that enables one to perceive space or size.
- retrofittable
- retrofitter
- retroflection
- retroflex
- retroflexion
- retrogradation
- retrograde
- retrograde ejaculation
- retrogradely
- retrogress
- retrogression
- retrogressive
- retrogressively
- retrolental
- retronym
- retroocular
- retroperitoneal
- retropharyngeal
- retrorocket
- retrorse
- retrorsely
- retrospect
- retrospection
- retrospective
- retrospectively