A ring fastened to the guard of a dagger or sword to protect the wielder's hand.

to get (a passing vehicle) to stop and give one a ride, signalling to the driver by holding out one's thumb (as a hitchhiker) / to disapprove or reject

plural of black thumb

A lack of skill in gardening; brown thumb. / (more generally) An inability to make animals or plants in one's care thrive. / A person with a black thumb.

plural of e-thumb

present participle of thumb down

simple past tense and past participle of thumb down

Of a book, having a thumb index.

A series of alphabetically marked or otherwise labelled semicircular cut-outs in the fore edge of a large reference book, encyclopaedia, Bible, etc., that allows quick access to various parts of the text.

plural of thumb index