It was the shape of a dumbbell—two spheres joined together by a short middle bar.
I was taken aboard one of their dumbbell ships, and brought here.
It was something like a dumbbell, covered with marine growth where it had been above the sand, but fairly smooth under it.
The next day he calmly chose the seat in front of the dumbbell—and proceeded to write a perfect examination.
It's nice to feel she isn't being wasted on some dumbbell, isn't it?
And hanging on patrol over this polar basin were two more of the dumbbell ships.
But a woman is at once given away: she look like a dumbbell run over by an express train.
Above it, they caught a flicker from the forest of masts and the glint from a dumbbell ship.
Of unusual shape, both round and flat, so a cross-section looks like a dumbbell with angular ends.
"weighted bar used for exercise," 1711, originally an apparatus like that used to ring a church bell, but without the bell (hence dumb); used for exercise but sometimes also to practice ringing changes. Figurative sense of "blockhead, stupid person" attested by 1918, American English college slang.
A stupid person; idiot: She's an awful dumb-bell
[1918+; fr dumbbell, a kind of weightlifter's barbell, attested from the 1880s]