Wordnet 3.0
NOUN (1)
1. 
 medium for radio and television broadcasting; 
- Example: "the program was on the air from 9 til midnight"- Example: "the president used the airwaves to take his message to the people"[syn: air, airwave]
WordNet (r) 3.0 (2006):
airwave
    n 1: medium for radio and television broadcasting; "the program
         was on the air from 9 til midnight"; "the president used
         the airwaves to take his message to the people" [syn:
         air, airwave]