the median, unpaired fin on the ventral margin between the anus and the caudal fin in fishes.
anal fin resembling the second dorsal, greyish, with the margin dull-purple.
Zoological Illustrations, Volume I William Swainson
a median ventral unpaired fin, situated between the anus and the tail fin in fishes, that helps to maintain stable equilibrium
- Anal fissure
anal fissure anal fissure n. A crack or slit in the mucous membrane of the anus.
- Anal fistula
anal fistula anal fistula n. A fistula opening at or near the anus, usually into the rectum above the internal sphincter.
- Anal orifice
anal orifice anal orifice n. See anus.
- Anal intercourse
noun a form of sexual intercourse in which the penis is inserted into the anus