The Collaborative International Dictionary
Disacquaint
Disacquaint \Dis`ac*quaint"\, v. t. [Pref. dis- + acquaint: cf. OF. desacointier.] To render unacquainted; to make unfamiliar. [Obs.]
While my sick heart
With dismal smart
Is disacquainted never.
--Herrick.
Wiktionary
disacquaint
vb. (context obsolete transitive English) To render unacquainted; to make unfamiliar.