Aid

noun

1. Help; assistance; succor, relief.

   "He came to my aid when I was foundering."

2. A helper; an assistant.
3. Something which helps; a material source of help.

   "Slimming aids include dietary supplements and appetite suppressants."

4. An historical subsidy granted to the crown by Parliament for an extraordinary purpose, such as a war effort.
5. An exchequer loan.