Sweet tango dancing — Uruguay’s first to enter (6)
I believe the answer is:
nougat
'sweet' is the definition.
(I know that nougat is a type of sweet)
'tango dancing uruguay's first to enter' is the wordplay.
'dancing' indicates an anagram.
'uruguay's first' becomes 'u' (1st letter of 'uruguay').
'to enter' indicates putting letters inside.
'tango' anagrammed gives 'nogat'.
'nogat' going around 'u' is 'NOUGAT'.
(Other definitions for nougat that I've seen before include "Chewy sweets made of nuts, sugar and albumen" , "confectionery" , "Chewy confection with nuts, cherries" , "Chewy sweet made of egg-white, nuts and sugar" , "Una got (anag) - a chewy sweet" .)