ally1
 
/
ˈalʌɪ/
n.
 (pl. allies)
 a person or organization that cooperates with another. 
▸a state formally cooperating with another for a military or other purpose.
 ▸
(the Allies)
 the countries that fought with Britain in the First and Second World Wars.
v.
  
/also 
əˈlʌɪ/
 
(allies, allying, allied)
  - 
(ally oneself with)
 side with.
 - 
(ally something to/with)
 combine a resource or commodity with (another) for mutual benefit.
 
Etymology
ME: from OFr. alier, from L. alligare ‘bind together’; cf. alloy.
ally2
 
/
ˈali/
n.
 (pl. allies)
 a toy marble.
Etymology
C18: perh. a dimin. of alabaster, choice marbles being made orig. of alabaster or marble.