Annual account signalman accurately keeps (7)
I believe the answer is:
almanac
'annual' is the definition.
(I know that almanac is a type of annual)
'account signalman accurately keeps' is the wordplay.
'keeps' indicates the answer is hidden within the clue.
'ALMANAC' can be found hidden inside 'account signalman accurately'.
(Other definitions for almanac that I've seen before include "Register" , "Yearly publication with calendar etc" , "Informative calendar" , "Kind of year-book like Old Moore's" , "Statistical annual" .)