Angle that is smaller than a right angle (less than 90Â°). Angle formed by two lines or two perpendicular planes that measures 90Â°. Symbol denoting that a straight line meets another at a right angle. Symbol denoting that two straight lines do not remain at a constant distance from one other. Symbol denoting that two straight lines remain at a constant distance from one another.
Constriction vs. Dilation. Constriction and dilation are opposite, but related, processes in the body. Whereas dilation is an opening or widening of a structure or passageway to increase material flow, constriction leads to a decrease in material flow by closing the passage.
conâ¢strict /kÉnËstrÉªkt/USA pronunciation v. conâ¢stricâ¢tive,adj. See-strict-. 1  to (cause to) be tight, narrower, or smaller; compress: [no object]The blood vessels constricted immediately.[~ + object]This medicine will constrict the blood vessels.onâ¢strict /kÉnËstrÉªkt/USA pronunciation v. conâ¢stricâ¢tive,adj. See-strict-. 1  to (cause to) be tight, narrower, or smaller; compress: [no object]The blood vessels constricted immediately.[~ + object]This medicine will constrict the blood vessels.