(especially of crustacean limbs and antennae) dividing to form two branches.
- ‘The appendages are primitively branched, and although this condition is modified in many species, adults always have at least some biramous appendages.’
- ‘The anteriormost five abdominal appendages are, almost without exception, biramous.’
- ‘An answer lies, he says, in the origin and modification of the ancestral biramous limb.’
- ‘My biramous appendages are quivering, Mr. President.’
- ‘About ten limbs appear to have been present, which may have been biramous.’
Late 19th century: from bi- two + ramus + -ous.