____ Falls (7)
'falls' is the definition.
('tumble' can be a synonym of 'fall')
This is the entire clue.
(Another definition for tumbles that I've seen is " Falls headlong, like Jill after Jack".)
'falls' is the definition.
(Niagara Falls)
This is the entire clue.
(Other definitions for niagara that I've seen before include "Large water falls" , "North American waterfalls" , "Horseshoe, American and Bridal Veil Falls, collectively" , "River flowing from Lake Erie into Lake Ontario" , "Waterfall at Iran aga" .)