This process is referred to as univerbation. An example from English is the word notwithstanding, which derives historically from the word not and the participle withstanding. In modern English it counts as a single word, namely, as a preposition, as in the prepositional phrase notwithstanding his request (compare the ungrammatical withstanding his request). Further examples are the conjunction because from Middle-English bi + cause 'by cause of', parallel to French par cause […]

Friday night I crashed your party. / Saturday I said I'm sorry. / Sunday came 'n' [you] trashed me out again.

Janus Dyes. Named after the God, Janus with two faces since they often exhibit two colors.

“But next time—” Night vanished before the guard could finish—just kind of disappeared like Batman—which Viv found almost as annoying as the fact that he'd dragged her down a well. He didn't think he had to explain himself?