Rules out coordinate, without doubt (6)
I believe the answer is:
surely
'without doubt' is the definition.
(I've seen this before)
'rules out coordinate' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'coordinate' becomes 'Y' (as in X and Y coordinates on a grid).
'rules' with letters rearranged gives 'surel'.
'surel'+'y'='SURELY'
(Other definitions for surely that I've seen before include "that's for certain" , "it would seem ironic?" , "Without doubt, certainly" , "With certainty" , "Confidently" .)