Blank charter on Gibraltar not entirely backed (6)
I believe the answer is:
ignore
'blank' is the definition.
(I've seen this before)
'charter on gibraltar not entirely backed' is the wordplay.
'not entirely' says the answer is hidden in the clue.
'backed' is a reversal indicator.
'erongi' can be found hidden inside 'charter on gibraltar'.
'erongi' back-to-front is 'IGNORE'.
(Other definitions for ignore that I've seen before include "Brush off" , "Forget" , "Region in which to snub" , "bypass" , "'Disregard, overlook (6)'" .)