I thought she was acting foolishly, but I 'bit my tongue' [='held my tongue'] and didn't say anything.
The news of their engagement 'set tongues wagging'. = 'Tongues were wagging' over their engagement.
He speaks English fluently but his 'mother tongue' [='native language, first language'] is Chinese.
(..) I play hard, I solder even harder. Sometimes he solders at home with his shirt off. It's like a beer commercial. (blows, clicks tongue) Well, we got to make a run to the hardware store. How can you call yourself a scientist and run out of solder? Well, funny story. (..)2016 TvShow: The Big Bang Theory Title: The Solder Excursion Diversion Season: 9 Episode 19