Order to run my bath — it's apocryphal (5,4)
I believe the answer is:
urban myth
'it's apocryphal' is the definition.
(urban myths are apocryphal or possibly untrue)
'order to run my bath' is the wordplay.
'order to' indicates anagramming the letters (a different order to the letters).
'run'+'my'+'bath'='runmybath'
'runmybath' with letters rearranged gives 'URBAN MYTH'.
(Other definitions for urban myth that I've seen before include "Very plausible but untrue story" , "yarn given an unlikely twist" , "Legend - 1 8 across?" .)