Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
clinch [klɪntʃ] vt (deal) заключа́ть (заключи́ть perf) (argument) разреша́ть (разреши́ть perf)
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.