n. 25B6; verb
she's constantly nagging me : HARASS, keep on at, go on at, badger, give someone a hard time, chivvy, hound, harry, criticize, find fault with, moan at, grumble at; henpeck; informal hassle; N. Amer. informal ride; Austral. informal heavy.
this has been nagging me for weeks : TROUBLE, worry, bother, plague, torment, niggle, prey on one's mind; annoy, irritate; informal bug, aggravate.
25B6; noun she's such a nag : SHREW, nagger, harpy, termagant, harridan; archaic scold.