a. and sb. [ad. mod.L. abdōmināl-is, f. abdōmen, abdōmin-; see -AL.]
A. adj.
1. Anat. Of or pertaining to the abdomen: ventral.
1746. Dr. R. James, Introd. to Moffet’s Health’s Impr., 8. The perpetual Compressure of the Stomach, and all the abdominal Viscera.
1836. Todd, Cycl. Anat. & Phys., I. 16. A degree of antagonism exists between the diaphragm and the abdominal muscles.
1870. Rolleston, Animal Life, 7. The walls of the abdominal and pelvic cavities.
1874. Wood, Nat. Hist., 553. That which is found on the under surface and in front of the vent is called the abdominal fin.
1879. Syd. Soc. Lex., 8. In man the respiration is said to be abdominal, in woman thoracic.
2. Zool. Belonging or attached to the abdomen of insects and crustacea.
1874. Lubbock, Orig. Metam. Insects, I. 7. Like caterpillars, having three pairs of legs and in the former case abdominal pro-legs as well.
1877. Huxley, Anat. Inv. An., vi. 346. Cynthia has its branchial appendages attached to the abdominal members.
3. Zool. Epithet of an order of fishes, a division of the soft-finned group of the Osseous fishes, having the ventral fins under the belly, as in the common carp, salmon, herring, etc.
1835. Kirby, Hab. & Inst. An., I. ii. 113. The herring … belongs to the tribe called abdominal fishes, or those whose ventral fins are behind the pectoral.
1847. Carpenter, Zool., 573. [These] have greater facility of ascending and descending than the abdominal fishes.
1854. Badham, Prose Halieutics, 235. That grand ichthyological section called abdominal, of which the leading feature is to have the belly-fins suspended behind the pectorals or side-fins.
B. sb. An abdominal fish; in pl. Abdominals, more commonly L. ǁ Abdominales, the order of soft-finned Osseous fishes, which have the ventral fins under the abdomen and behind the pectorals.
