emphasis You use needless to say when you want to emphasize that what you are about to say is obvious and to be expected in the circumstances. Our budgie got out of its cage while our cat was in the room. Needless to say, the cat moved quicker than me and caught it. = of course
Something that is needless is completely unnecessary. But his death was so needless `I have never knowingly exposed any patient to needless risks,' he said. + needlessly need·less·ly Half a million women die needlessly each year during childbirth
unnecessary and unwarranted; "a strikers' tent camp was burned with needless loss of life"