The Collaborative International Dictionary of English v.0.48:

Citrange \Cit"range\, n. [Citrus + orange.]
   A citrous fruit produced by a cross between the sweet orange
   and the trifoliate orange (Citrus trifoliata). It is more
   acid and has a more pronounced aroma than the orange; the
   tree is hardier. There are several varieties.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

citrange
    n 1: more aromatic and acidic than oranges [syn: citrange,
         citrange tree, Citroncirus webberi]
    2: more aromatic and acid tasting than oranges; used in
       beverages and marmalade