Wordnet 3.0
ADVERB (1)
1. 
 one behind the other; 
- Example: "ride tandem on a bicycle built for two"- Example: "riding horses down the path in tandem"[syn: tandem, in tandem]
WordNet (r) 3.0 (2006):
in tandem
    adv 1: one behind the other; "ride tandem on a bicycle built for
           two"; "riding horses down the path in tandem" [syn:
           tandem, in tandem]