Verb
(transitive) To put (someone) into (a particular state, emotion etc.). [from 19th c.]
(intransitive) To cohere with; to accord with, to be in keeping with. [from 20th c.]
(transitive) To make (someone) focus or concentrate on (something); to make (someone) understand. [from 20th c.]
Walter wasn't on the same page as the rest of us at first, but we talked about it and keyed him into it.