lollipop

n.

A confection consisting of a piece of hard candy attached to the end of a small stick.

Also called lolly.

popsicle

n. American English

A frozen water dessert on a stick that is colored and flavored. A frozen stick confection.

It is called a popsicle in the United States and Canada due to the early popularity of the Popsicle brand, and the word has entered the vernacular there to mean any ice pop, irrespective of brand.

Synonym:

UK: ice lolly
Australia: ice block, or icy pole
New Zealand: ice block
Ireland: ice pop