Wordnet 3.0
VERB (1)
1. 
 lose an upright position suddenly; 
- Example: "The vase fell over and the water spilled onto the table"- Example: "Her hair fell across her forehead"[syn: fall, fall down]
WordNet (r) 3.0 (2006):
fall down
    v 1: lose an upright position suddenly; "The vase fell over and
         the water spilled onto the table"; "Her hair fell across
         her forehead" [syn: fall, fall down]