di·la·tion 
(dī-lāshən, dĭ-)
(dī-lāshən, dĭ-)n.
1.
a. The act of expanding or enlarging or the state of being expanded or enlarged: dilation of the cervix during labor.
b. The condition of being abnormally expanded or enlarged, as of an organ, orifice, or tubular structure in the body.
2. A lengthy spoken or written discussion on a topic: "an Edith Whartonesque dilation on a social class steeped in hypocrisy" (Caroline Seebohm).