de·cal·co·ma·ni·a 
(dē-kăl′kə-mānē-ə, -mānyə)
(dē-kăl′kə-mānē-ə, -mānyə)n.
1. The process of transferring pictures or designs printed on specially prepared paper to materials such as glass or metal.
2. A decal.
[French décalcomanie, from dēcalquer, to transfer a tracing (de-, off, from from Latin dē-; see DE- + calquer, to trace; see CALQUE) + manie, craze (from its popularity in the 19th century) (from Late Latin mania, madness; see MANIA).]
- observant
- observantly
- observation
- observational
- observationally
- observatory
- observe
- observer
- observingly
- obsess
- obsession
- obsessional
- obsessionally
- obsessive
- obsessive-compulsive
- obsessive-compulsive disorder
- obsessive-compulsive personality disorder
- obsessively
- obsessiveness
- obsessor
- obsidian
- obsolesce
- obsolescence
- obsolescent
- obsolescently