Emily Dickinson Lexicon

PEG, n. [This is probably from the root of L. pango, pactus, Gr. πηγνυμι; denoting that which fastens, or allied to beak and picket.]

1. A small pointed piece of wood used in fastening boards or other work of wood, &c. It does the office of a nail. The word is applied only to small pieces of wood pointed; to the larger pieces thus pointed we give the name of pins, and pins in ship carpentry are called tree-nails or trenails. Coxe, in his Travels in Russia, speaks of poles or beams fastened into the ground with pegs.
2. The pins of an instrument on which the strings an strained. – Shak.
3. A nickname for Margaret. To take a peg lower, to depress; to lower. – Hudibras.