* एड़ी (edi) - This is the most common word for "heel" and refers to the back part of the foot.
* ऊँची एड़ी (oonchi edi) - This literally means "high heel" and refers to the raised part of a shoe that the heel of the foot rests on.
So, if you're talking about the back of the foot, you would use "एड़ी." If you're talking about the part of the shoe, you would use "ऊँची एड़ी."