/
ˈvɛdʒtəb(ə)l, 
ˈvɛdʒɪtə-/
n.
  - a plant or part of a plant used as food.
 - informal, derogatory a person who is incapable of normal mental or physical activity, especially through brain damage. 
▸a person with a dull or inactive life.
 
Etymology
ME (in the sense ‘growing as a plant’): from OFr., or from late L. vegetabilis ‘animating’, from L. vegetare (see vegetate).