Other forms: handshakes
A handshake is the act of greeting someone by clasping their hand in yours and giving a brief, firm, up-and-down shake. It's fairly formal to greet another person with a handshake.
It's appropriate to use a handshake, usually with the right hand, when you're being introduced to someone or presenting yourself at a job interview, for example. You can also use a handshake to seal an agreement or deal with another person. Handshakes were used as far back as the 5th century BCE in ancient Greece, and some historians believe the handshake was initially meant as a gesture proving that neither person held a weapon.