IPA: /ˌdɛkəlˈkoʊməˌniə/
KK: /dɛˌkæl.kəˈmeɪ.ni.ə/
The art or method of transferring images or designs from specially prepared paper to surfaces like glass or metal.
She used decalcomania to create beautiful designs on the glass vase.
Decalcomania is formed from "de-" (meaning down or away) and "calcomania" (from French *calque* meaning to transfer and *manie* meaning madness or obsession). The term refers to the process of transferring designs from specially prepared paper to another surface, often implying an obsession with this decorative technique.
Think of 'transferring' designs ('calcomania') in a way that feels like an 'obsession' ('manie') — that's why decalcomania refers to this artistic transfer technique.