Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
mortgage [ˈmɔːgɪdʒ] n ипоте́чный креди́т, ипоте́чная ссу́да
vt закла́дывать (заложи́ть*perf)
to take out a mortgage брать*(взять*perf) ипоте́чный креди́т
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.