Handshake
From Tardis Wiki, the free Doctor Who reference
As Jo Grant explained to Latep the Thal, a handshake was an "old Earth custom" which entailed the clasping of hands between two people, showing that they were good friends and that we were pleased to meet one another. (TV: Planet of the Daleks)
Following the destruction of Davros' right and last hand, the Sixth Doctor facetiously offered him a handshake. (TV: Revelation of the Daleks)