A person or thing causing trouble
annoyance, difficult situation, bother, bind, hindrance, difficulty, task, puzzle, predicament, plight, problem, fear, worry, concern, inconvenience, nuisance, disturbance, calamity, catastrophe, crisis, negative function, delay, quarrel, dispute, affliction, intrusion, disquiet, irritation, trial, pain, pique, ordeal, discomfort, injury, adversity, hang-up, case, bore, gossip, problem child, pestiferous person, meddler, pest, tease, tiresome person, talkative person, inconsiderate person, intruder, troublemaker, fly in the ointment*, monkey wrench*, headache*, smart aleck*, buttinski*, brat*, handful*, holy terror*, bad news*, botheration*, peck of trouble*; see also care 2.
Antonyms aid*, help, comfort*.