handshaker
/ˈhan(d)ʃeɪkə/noun
1A person who (habitually) shakes hands.
2 US informal. A person who makes a show of being genial, especially one who attempts to curry favour with insincere flattery; a sycophant, a toady.
Origin
Mid 19th century; earliest use found in Harriet Martineau (1802–1876), writer and journalist. From hand + shaker, after to shake hands.