Bivver, I suppose, is a cross between, “brrrrrrrr” and quiver. It’s a movement and sometimes a sound that’s made. Generally it’s a
teeth chattering, particularly your bottom lip and your chin shaking.
And I associated it mainly with cold. It also might be used if you see a child on the verge of tears, for instance. You see them… bivver in the bottom lip, before they break into tears And that’s where it will be used too. If I’m waiting to go to school as a kid, you know, and you’re leaned up against a pole and as a northeast wind whistling in, You’re trying to get some shelter and you are literally bivvvvvvering… then that’s what the word means.