sleight of hand /ˌslaɪt əv ˈhænd/ BrE AmE noun [uncountable]
[ Date: 1400-1500 ; Origin: sleight 'skill, trick' (13-20 centuries) from Old Norse slgth , from slgr ; ⇨ ↑ sly ]
1 . the use of quick and skilful movements with your hands when doing a magic trick, so that people cannot understand how you did the trick
2 . the use of skilful tricks and lies in order to deceive someone