Occurring every year (6)
(Other definitions for annual that I've seen before include "(Of plant) living for a year or less" , "Book published yearly" , "Twelve-monthly" , "Occuring once a year" , "Yearly publication" .)
(Other definitions for annually that I've seen before include "at regular intervals" , "As Christmas is coming" , "Every year" , "as MOTs must be renewed" .)