Wordnet 3.0
NOUN (1)
1. 
 a prefabricated structure; 
ADJECTIVE (1)
1. 
 manufactured in standard sizes to be shipped and assembled elsewhere; 
- Example: "a pre structure"
WordNet (r) 3.0 (2006):
prefab
    adj 1: manufactured in standard sizes to be shipped and
           assembled elsewhere; "a pre structure"
    n 1: a prefabricated structure