Colonist ignoring large type of dog (6)
I believe the answer is:
setter
'type of dog' is the definition.
(I know that setter is a type of gun dog)
'colonist ignoring large' is the wordplay.
'colonist' becomes 'settler' (synonyms).
'ignoring' indicates named letters should be taken away.
'large' becomes 'L' (eg in clothes sizes).
'settler' with 'l' removed is 'SETTER'.
(Other definitions for setter that I've seen before include "pointer" , "Crossword maker; dog" , "Jelly, perhaps" , "A dog trained to stand still when it scents game" , "Crossword composer" .)