If I scout it carelessly, it's imaginary (10)
I believe the answer is:
fictitious
'imaginary' is the definition.
(I've seen this before)
'if i scout it carelessly' is the wordplay.
'carelessly' is an anagram indicator.
'if'+'i'+'scout'+'it'='ifiscoutit'
'ifiscoutit' with letters rearranged gives 'FICTITIOUS'.
'it's' acts as a link.
(Other definitions for fictitious that I've seen before include "Mythical" , "Not true" , "Invented" , "Imaginary" , "Make-believe" .)