Wordnet 3.0
ADVERB (1)
1. 
 speaking or singing at the same time; 
 simultaneously; 
- Example: "they shouted `Yes!' in unison"- Example: "they responded in chorus to the teacher's questions"[syn: in unison, in chorus]
WordNet (r) 3.0 (2006):
in chorus
    adv 1: speaking or singing at the same time; simultaneously;
           "they shouted `Yes!' in unison"; "they responded in
           chorus to the teacher's questions" [syn: in unison, in
           chorus]