ADJECTIVE (1)

1. derived from what is primary or original by two intermediate steps;
- Example: "a thirdhand report"


ADVERB (1)

1. by doubly indirect means;
- Example: "I got the news thirdhand"

WordNet (r) 3.0 (2006):

thirdhand
    adv 1: by doubly indirect means; "I got the news thirdhand"
    adj 1: derived from what is primary or original by two
           intermediate steps; "a thirdhand report"