an extra hand in some watches and clocks that moves round to indicate the seconds

(of goods) having had a previous owner; not new

a second-hand car

(of information or experience) accepted on another's authority and not from original investigation

second-hand knowledge of her country

on the basis that something has had a previous owner

tips on the pitfalls to avoid when buying second-hand

on the basis of what others have said; indirectly

I was discounting anything I heard second-hand