Disadvantage the Spanish suffered originally (4)
I believe the answer is:
loss
'disadvantage' is the definition.
(I've seen this before)
'the spanish suffered originally' is the wordplay.
'the spanish' becomes 'los' ('the' in Spanish**).
'originally' indicates taking the first letters.
The first letter of 'suffered' is 's'.
'los'+'s'='LOSS'
(Other definitions for loss that I've seen before include "Forgetting" , "Financial shortfall" , "Red figures on a balance sheet or ledger" , "sacrifice?" , "(Sports) defeat" .)