Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
grass [grɑːs] n трава́#; (lawn) газо́н; (BRIT) (inf)(informer) стука́ч#; (:ex-terrorist) доно́счик
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.