adj.
1.having no cogency or legal force
2.no longer valid invalid n.
1.someone who is incapacitated by a chronic illness or injury invalid v.
1.force to retire, remove from active duty, as of firemen
2.injure permanently
Idiom of the Day
stumbling block
something that prevents or obstructs progress
The salary issue was a stumbling block in the negotiations between the company and the union.