Noun
tuning peg (plural tuning pegs)
Synonym of tuning key
It is the distance between the tuning peg and the soundboard, as well as the tension and weight of the string, which decide the pitch of the string. Source: Internet
The top end of each string is secured on the crossbar or neck of the instrument, where each will have a tuning peg or similar device to adjust the pitch of that string. Source: Internet