The Collaborative International Dictionary of English v.0.48:

corticotrophin \corticotrophin\, corticotropin \corticotropin\n.
   a growth hormone produced by the anterior pituitary gland; it
   stimulates the adrenal cortex; -- called also
   adrenocorticotropin and abbreviated ACTH.

   Syn: adrenocorticotropic hormone, adrenocorticotrophic
        hormone, adrenocorticotropin, adrenocorticotropin,
        corticotrophin, ACTH.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

corticotropin
    n 1: a hormone produced by the anterior pituitary gland that
         stimulates the adrenal cortex [syn: adrenocorticotropic
         hormone, adrenocorticotrophic hormone, ACTH,
         adrenocorticotropin, adrenocorticotrophin,
         corticotropin, corticotrophin]