County is grand nearly the whole time (6)
I believe the answer is:
galway
'county' is the definition.
(county of Ireland)
'grand nearly the whole time' is the wordplay.
'grand' becomes 'g' (synonyms).
'nearly' means to remove the last letter.
'the whole time' becomes 'always'.
'always' with its final letter removed is 'alway'.
'g'+'alway'='GALWAY'
'is' is the link.
(Other definitions for galway that I've seen before include "Connacht city" , "Western City of the Tribes" , "W. Irish town, county, bay" , "flautist" , "part of Ireland" .)