per·i·proct 
(pĕrə-prŏkt′)
(pĕrə-prŏkt′)n.
The flexible membrane around the anus of certain invertebrates, especially echinoids.
[PERI- + Greek prōktos, anus.]
- unable
- unabridged
- unaccented
- unacceptability
- unacceptable
- unacceptably
- unaccommodated
- unaccompanied
- unaccomplished
- unaccountability
- unaccountable
- unaccountably
- unaccounted-for
- unaccredited
- unaccustomed
- unaccustomedly
- unachievable
- unacknowledged
- una corda
- unacquainted
- unaddressed
- unadjusted
- unadorned
- unadulterated
- unadventurous