Rodeo lasso (4)
'rodeo lasso' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for riata that I've seen before include "Lariat made from strange tiara" , "lasso" , "Rope with noose" , "Tiara turned into a cowboy's rope" , "Spanish lariat" .)
(Other definitions for rope that I've seen before include "Lasso?" , "will it bring in easy money when old?" , "Guy" , "murder weapon" , "Stout cord" .)