forgetfulfor‧get‧ful /fəˈɡetfəl $ fər-/ adjective 
- My grandfather's getting so forgetful - I have to remind him to take his medication.
- My grandfather is getting more forgetful.
- She was easily distracted and forgetful at school.
- Also he appeared to have corrupted her: she was alternately prickly and forgetful.
- Ellen was about as disorganized and forgetful as any fourth grade child in memory.
- In the aftermath she nestled in his arms, forgetful of the time.
- Indeed I was forgetful, pathologically so, and for this too I felt nothing but remorse.
- They can also be forgetful or very tired and perhaps bad tempered.
someone who often forgets things► have a bad/terrible/awful etc memory to not be good at remembering facts or information: · I'm sorry for forgetting to phone her - I have a terrible memory.have a bad/terrible/awful etc memory for: · I have a bad memory for names.
► forgetful usually someone who is forgetful often forgets things, especially things they have to do: · My grandfather's getting so forgetful - I have to remind him to take his medication.· She was easily distracted and forgetful at school.
► absent-minded someone who is absent-minded often forgets things because they are thinking about other things: · He's a brilliant scientist but hopelessly absent-minded.
► have a memory like a sieve British informal to not be able to remember facts or information, even for a short time: · You'd better remind him about the party - he's got a memory like a sieve!
adjectiveforgetfulforgettable ≠ unforgettableadverbforgetfullyunforgettablynounforgetfulnessverbforget