n.
   - help or support.
 - material help given to a place in need.
 - historical a grant of subsidy or tax to a king.
 
v.
 help in the achievement of something.
 
  Phrase
  
    - in aid of
 chiefly Brit. in support of.  - what's 
(all)
 this in aid of?
 Brit. informal what is the purpose of this? 
   
  Etymology
  ME: from OFr. aide (n.), aidier (v.), based on L. adjuvare, from ad- ‘towards’ + juvare ‘to help’.