a passing acquaintance with something

a passing acquaintance with (someone or something)

A very limited knowledge of or familiarity with a given person or thing. I'll help you as best I can, but I only have a passing acquaintance with property laws. I have a passing acquaintance with him, but I wouldn't feel comfortable asking him to help me on this project.

a passing acquaintance with something

If you have a passing acquaintance with something, you only know a little about it. These days a theatre-goer needs more than a passing acquaintance with science. Note: You can also say that you have a nodding acquaintance with something. We chatted for a little about poetry, with which he showed considerably more than a nodding acquaintance.