hard·en·er 
(härdn-ər)
(härdn-ər)n.
One that hardens, especially a substance added to varnish or paint to give it a harder surface or finish.
- superhumanity
- superhumanly
- superimposable
- superimpose
- superimposition
- superincumbence
- superincumbency
- superincumbent
- superinduce
- superinduction
- superinfect
- superinfection
- superintend
- superintendence
- superintendent
- superior
- Superior
- superior conjunction
- superior court
- superiority
- superiority complex
- superiorly
- superior planet
- superjacent
- superjet