Wordnet 3.0
ADVERB (1)
1. 
 never except when; 
- Example: "call me only if your cold gets worse"[syn: only, only if, only when]
WordNet (r) 3.0 (2006):
only if
    adv 1: never except when; "call me only if your cold gets worse"
           [syn: only, only if, only when]