Is secondhand a noun?
The word 'second hand' is an open spaced compound noun as a word for the third hand of a clock or a watch that measures the seconds. The word 'secondhand' (a closed compound word) is an adjective that describes a noun as taken from someone else or having been owned before (a secondhand car, secondhand information), and an adverb used to modify a verb, an adjective, or another adverb (We're buying secondhand to save money).