Upwords Is a Variation of __ With Stacking Letters

This page is the CodyCross answer for the clue below from Sports, Group 157, Puzzle 3 (Competitions).

Question is: Upwords Is a Variation of __ With Stacking Letters

and the answer is: SCRABBLE

Word Meaning:

SCRABBLE — (intransitive) To scrape or scratch powerfully with hands or claws.

Definitions from Wiktionary.

Upwords is a variation of __ with stacking letters — CodyCross Answer | CodyCross Solutions