dilation
di.la.tion \di--'la--sh*n, dil-'a--\ n 1: the act of dilating : the state of being dilated : EXPANSION, DILATION 2: the action of stretching or enlarging an organ or part of the body
Webster's English Dictionarydi.la.tion \di--'la--sh*n, dil-'a--\ n 1: the act of dilating : the state of being dilated : EXPANSION, DILATION 2: the action of stretching or enlarging an organ or part of the body