If you have a passing acquaintance with someone, you know them slightly. To those with only a passing acquaintance he is charming and engaging. Note: You can also say that you have a nodding acquaintance with someone. And of course, he can now claim — after his first summit as head of government — more than a nodding acquaintance with his fellow leaders. Note: You can call a person a passing acquaintance or a nodding acquaintance if you know them slightly. He was no more than a passing acquaintance of Wright.

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.