Wordnet 3.0
NOUN (2)
1. 
 biometric identification by scanning a person's face and matching it against a library of known faces; 
- Example: "they used face recognition to spot known terrorists"[syn: face recognition, facial recognition, automatic face recognition]
2.  the visual perception of familiar faces; 
WordNet (r) 3.0 (2006):
face recognition
    n 1: biometric identification by scanning a person's face and
         matching it against a library of known faces; "they used
         face recognition to spot known terrorists" [syn: face
         recognition, facial recognition, automatic face
         recognition]
    2: the visual perception of familiar faces