Definition of thumb verb from the Oxford Advanced American Dictionary

     

    thumb

     verb
    verb
    NAmE//θʌm//
     
    Verb Forms present simple I / you / we / they thumb
     
    he / she / it thumbs
     
    past simple thumbed
     
    -ing form thumbing
     
     
    jump to other results
  1. 1 [intransitive, transitive] to make a signal with your thumb to passing drivers to ask them to stop and take you somewhere + adv./prep. He had thumbed all across Europe. thumb a ride We managed to thumb a ride with a truck driver.
  2. 2[transitive] thumb something (+ adv./prep.) to touch or move something with your thumb She thumbed off the safety catch of her pistol. see also well-thumbed
  3. Idioms
    thumb your nose at somebody/something
     
    jump to other results
    to make a rude sign with your thumb on your nose; to show that you have no respect for someone or something The company just thumbs its nose at the legislation on pollution.
    Phrasal Verbsthumb through something
See the Oxford Advanced Learner's Dictionary entry: thumb