for·get·ful 
/fɚˈgɛtfəl/ adjective
/fɚˈgɛtfəl/ adjective [more forgetful; most forgetful] 1 : tending to forget things : forgetting things often or easily
▪ He became forgetful in his old age. 2 — used to say that someone has forgotten something ▪ She has been forgetful of her duties. [=she has forgotten/neglected her duties]
▪ He became forgetful in his old age.
— for·get·ful·ly adverb
▪ He forgetfully left the lights on.
▪ He forgetfully left the lights on.
— for·get·ful·ness noun [noncount]
▪ His forgetfulness grew worse in his old age.
▪ His forgetfulness grew worse in his old age.
