vaguen

The story

From vague + -en (suffix forming transitive verbs from adjectives, meaning ‘to make [adjective]’), coined by Irish writer Samuel Beckett (1906–1989), apparently first in a manuscript note to himself on an initial typescript of his play Happy Days (1961).

First known use, by meaning

• from 1961 To make (something) vague or more vague; to blur, to obscure.