The Collaborative International Dictionary of English v.0.48:

Humulin \Hu"mu*lin\, n. [NL. Humulus, the genus including the
   hop.]
   An extract of hops.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Humulin
    n 1: a form of insulin (trade name Humulin) made from
         recombinant DNA that is identical to human insulin; used to
         treat diabetics who are allergic to preparations made from
         beef or pork insulin [syn: recombinant human insulin,
         Humulin]