Former Tommies travelling to Spain (8)
I believe the answer is:
sometime
'former' is the definition.
(I've seen this before)
'tommies travelling to spain' is the wordplay.
'travelling' indicates an anagram.
'to spain' becomes 'e' (abbreviation for Espana).
'tommies' is an anagram of 'sometim'.
'sometim'+'e'='SOMETIME'
(Other definitions for sometime that I've seen before include "In the future, we don't know when" , "ex?" , "Formerly" , "At a future unknown period" , "An indeterminate date in the future" .)