Expressions used in Everyday Spoken English in Social and Professional contexts
To ‘twiddle your thumbs’ is to rotate your thumbs around each other while your hands are together. When you say you are ‘twiddling your thumbs’ it means you are idle or do not have anything useful to do. If someone accuses you of ‘twiddling your thumbs’ they mean to say that you are not working hard or doing anything of importance. This is a casual idiom used more often in social contexts.