drawstring
drawstring trousers

have on
she had her new trousers on

hitch up
to hitch up one's trousers

kneed
kneed trousers

let out
the trousers have been let out

match
...coat and trousers to match

pocket
trousers pocket

pyjama
pyjama trousers

pyjamas
pyjama trousers

seat
to seat a pair of trousers

side
his trousers were on the short side

slack
...of his trousers

trousers
a pair of trousers

vest
coat, vest and trousers

wear
to wear a hole in one's trousers