qua·dru·plet 
/kwɑˈdru:plət/ noun
plural qua·dru·plets /kwɑˈdru:plət/ noun [count] : one of four babies that are born at the same time to the same mother — usually plural ▪ She had (a set of) quadruplets. [=she gave birth to four babies] — compare quintuplet, sextuplet, triplet, twin
