Oxford Advanced American Dictionary

Definition of peg noun from the Oxford Advanced Learner's Dictionary

peg

noun
peg pronunciation English peɡ peg pronunciation American peɡ
 
1 a short piece of wood, metal or plastic used for holding things together, hanging things on, marking a position, etcThere's a peg near the door to hang your coat on.Mark the boundary with pegs.2 (also tent peg) a small pointed piece of wood or metal that you attach to the ropes of a tent and push into the ground in order to hold the tent in place3 (also clothes peg) (both British English) (North American English clothespin) a piece of wood or plastic used for attaching wet clothes to a clothes line4 (also tuning peg) a wooden, metal or plastic screw used for making the strings of a musical instrument tighter or looser
Idioms

off the peg

(British English) (North American English off the rack) (of clothes) made to a standard average size and not made especially to fit youHe buys his clothes off the peg.off-the-peg fashions

bring/take somebody down a peg (or two)

to make somebody realize that they are not as good, important, etc. as they think they are
He needed to be taken down a peg or two.

a peg to hang something on

something that gives you an excuse or opportunity to discuss or explain something
The character provides a peg to hang the writer's political ideas on.
 more at a square peg (in a round hole) at square adjective