safety
bobby (AmE), hair (usually hairpin)
bent, straight (both AmE)
drawing (BrE), push (AmE) (usually pushpin)
tie (usually tiepin)
diamond, jewelled/jeweled, metal, silver, steel
clothes (usually clothespin) (clothes peg in BrE)

drive in, insert, stick in
The map had a lot of little pins stuck into it.

pull out, remove

lapel
flag
an American flag lapel pin

wear

carefully, neatly
She carefully pinned the two pieces of cloth together.

firmly, securely
back, on, together, up
Her hair was pinned back.
pictures pinned up on the walls

onto
The poster had been pinned onto a large board.

to
Maps were pinned to the walls.

pin sth in place

helplessly
down
He was pinned down on the floor.

against
He pinned her against the wall.

behind
His arms were pinned behind his back.

to
She was pinned helplessly to the desk.

exactly, precisely
The difference between the two approaches is hard to pin down precisely.

be difficult to, be hard to

Pin is used with these nouns as the object:
blame, brooch, faith, hope