Anal fin
the median, unpaired fin on the ventral margin between the anus and the caudal fin in fishes.
Historical Examples
anal fin resembling the second dorsal, greyish, with the margin dull-purple.
Zoological Illustrations, Volume I William Swainson
noun
a median ventral unpaired fin, situated between the anus and the tail fin in fishes, that helps to maintain stable equilibrium
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- 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
- Anal pecten
anal pecten anal pecten n. The middle third of the anal canal.