On the contrary, noticed trainer outside, beside the Spanish loafer (7)
I believe the answer is:
wastrel
'loafer' is the definition.
(thesaurus)
'on the contrary noticed trainer outside beside the spanish' is the wordplay.
'on the contrary' is a reversal indicator (letters in the opposite or contrary direction).
'noticed' becomes 'saw' (I've seen this in another clue).
'outside' means to remove the middle letters.
'beside' is a charade indicator (letters next to each other) (I've seen this in other clues).
'the spanish' becomes 'el' ('the' in Spanish).
'trainer' with its centre removed is 'tr'.
'saw' backwards is 'was'.
'was'+'tr'+'el'='WASTREL'
(Other definitions for wastrel that I've seen before include "A useless, good for nothing fellow" , "Useless person" , "Worthless person" , "Spendthrift" , "Layabout" .)