bidding vs pre-empt

bidding and pre-empt both are nouns.

Word	Noun	Adjective	Verb	Adverb
bidding	Yes	No	No	No
pre-empt	Yes	No	No	No

As nouns, pre-empt is a hyponym of bidding; that is, pre-empt is a word with a more specific, narrower meaning than bidding:

bidding: (bridge) the number of tricks a bridge player is willing to contract to make
pre-empt: a high bid that is intended to prevent the opposing players from bidding

Other hyponyms of bidding include contract, declaration, takeout, overbid, overcall, preempt, preemptive bid.

bidding (noun)	pre-empt (noun)
a request to be present	a high bid that is intended to prevent the opposing players from bidding
(bridge) the number of tricks a bridge player is willing to contract to make
an authoritative direction or instruction to do something