palmrenthesis
In conversation, the cupping of the hands inward to indicate an interjected explanatory or qualifying remark in a sentence. Similar to the "air quote."
"I finished watching The Sting ::put up palmrenthesis:: which is an amazing movie, btw ::put down palmrenthesis:: when I realized I'd done no studying for my exam tomorrow so I'm totally screwed."
or,
"That pretentious asshole used palmrenthesis when he was telling me a story!"
or,
"That pretentious asshole used palmrenthesis when he was telling me a story!"