An
amendment created by a member of the United States
House of Representatives during the creation of a
bill. In Congressional debate, the
Speaker of the House extends 10 minutes for the purpose of debating each amendment. Very often, the person posing the amendment and the leader of the opposition to the amendment will use up their respective five minutes, leaving their
colleagues without any time to speak.
When this happens, representatives will pose a pro forma amendment, most often by saying the following:
Representative X: Mr. Speaker, I move to strike the last word.
By saying this, they are formally objecting to the last word of the amendment, thus proposing their own amendment, giving them five minutes to speak.
Pro forma amendments have become an increasingly common Parliamentary Debate tactic, since they are considered withdrawn after the five minutes.
Sources: C-SPAN Television