The Collaborative International Dictionary
Melotype
Melotype \Mel"o*type\, n. (Photog.) A picture produced by a process in which development after exposure may be deferred indefinitely, so as to permit transportation of exposed plates; also, the process itself.
Wiktionary
melotype
n. (context photography English) A picture produced by a process in which development after exposure may be deferred indefinitely, so as to permit transportation of exposed plates.