be on nodding terms (with someone)
To know someone only as an acquaintance. The two of us are just on nodding terms—I couldn't even tell you his name. I'm only on nodding terms with her sister, so I can't ask her for a favor like that.
be on nodding terms
know someone slightly.be on ˈnodding terms with somebody
know somebody not very well, but well enough to say ‘hello’ when you meet them: We’re on nodding terms with our neighbours but we don’t know anyone else at all.