The rest of the Spanish, yes, on some estancias (6)
I believe the answer is:
siesta
'the rest' is the definition.
(I've seen this before)
'the spanish yes on some estancias' is the wordplay.
'the spanish yes' becomes 'si' (Yes in Spanish).
'on some estancias' becomes 'esta' (I can't explain this - if you can you should give a lot more credence to this answer).
'si'+'esta'='SIESTA'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for siesta that I've seen before include "A mid-day nap in Spain" , "Catnap" , "Seat is found for a Spanish rest period" , "Afternoon relaxation" , "Afternoon break" .)