A dumbbell is a short bar with weights on either side which people use for physical exercise to strengthen their arm and shoulder muscles.
2. countable noun
If you call a person a dumbbell, you mean that they are stupid or foolish.
[informal, disapproval]
dumbbell in British English
(ˈdʌmˌbɛl)
noun
1. gymnastics, weightlifting
an exercising weight consisting of a single bar with a heavy ball or disc at either end
2.
a small wooden object shaped like this used in dog training for the dog to retrieve
3. slang, mainly US and Canadian
a foolish person
dumbbell in American English
(ˈdʌmˌbɛl)
noun
1.
a device usually used in pairs, consisting of round weights joined by a short bar, by which it is lifted or swung about in the hand for muscular exercise
2. US, Slang
a stupid person
Word origin
dumb + bell1: from orig. shape; (sense 2) cf. , sense dumb (sense 7)