Noun
cliticization (countable and uncountable, plural cliticizations)
(grammar) The process, or an instance, of a word becoming a clitic.
The term "postlexical clitic" is used for this narrower sense of the term. Klavans, Judith L. On Clitics and Cliticization: The Interaction of Morphology, Phonology, and Syntax. Source: Internet