noun
plural pins
[count] :a thin, pointed piece of stiff wire with a rounded head at one end that is used especially for fastening pieces of cloth - see picture at sewing; see also bobby pin, clothespin, drawing pin, hairpin, safety pin
[count] a thin, pointed piece of stiff wire with a decoration at one end - see also hatpin
b chiefly US :brooch
a small usually circular object that has writing and often a picture on it and that has a pin on the back so that it can be fastened to clothing, bags, etc.
[count] a thin piece of wood, metal, or plastic that is used for holding things together or for hanging one thing from another
a long, thin piece of metal that is used to fasten together the ends of broken bone
[count] Brit :one of the metal pieces that stick out from an electric plug and fit into a socket :prong
[count] :a thin piece of metal that is removed to trigger the explosion of a small bomb (called a grenade)
[count] golf :a long stick with a flag at the top that shows where the hole is on a green
[count] bowling :one of the usually white standing pieces that are knocked down with the ball - see also tenpin
pins [plural] informal :the legs of a person or animal
you could hear a pin drop
used to say that it was so quiet that the smallest noise could be heard
verb
always followed by an adverb or preposition pins; pinned; pinning
[+ obj] to fasten or attach (something) with a pin
to prevent or stop (someone or something) from moving by holding or pressing firmly against something
pin down
[phrasal verb]
pin (someone) down :to cause or force (someone) to make a definite statement or decision about something
pin down (something) or pin (something) down :to find out (something) with certainty
pin on
[phrasal verb]
pin (something) on (someone) :to say that (something) was done or caused by (someone)
pin (all) your hopes on (something) :to hope very much that (something) will help you or allow you to succeed