The Collaborative International Dictionary of English v.0.48:

Innominate \In*nom"i*nate\, a. [L. innominatus; pref. in- not +
   nominare to name.]
   1. Having no name; unnamed; as, an innominate person or
      place. [R.] --Ray.
      [1913 Webster]

   2. (Anat.) A term used in designating many parts otherwise
      unnamed; as, the innominate artery, a great branch of the
      arch of the aorta; the innominate vein, a great branch of
      the superior vena cava.
      [1913 Webster]

   Innominate bone (Anat.), the great bone which makes a
      lateral half of the pelvis in mammals; hip bone; haunch
      bone; huckle bone. It is composed of three bones, ilium,
      ischium, and pubis, consolidated into one in the adult,
      though separate in the fetus, as also in many adult
      reptiles and amphibians.

   Innominate contracts (Law), in the Roman law, contracts
      without a specific name.
      [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

INNOMINATE CONTRACTS, civil law. Contracts which have no particular names,
as permutation and transaction, are so called. Inst. 2, 10, 13. There are
many innominate contracts, but the Roman lawyers reduced them to four
classes, namely, do ut des, do ut facias, facio ut des, and facio ut facias.
(q. v.) Dig. 2, 14, 7, 2.