the.com/dilation

means The act or process of making something wider, larger, or more open — whether it's a pupil, a cervix, or a stretch of time in a physics equation.

from From Latin dilatare, 'to spread out or widen,' built from dis- ('apart') plus latus, 'wide.' That same latus also gives English words like 'latitude.' The 're' you might expect isn't there — 'dilate' took a slightly different path into English than its cousin 'dilatory,' which comes from a related but distinct Latin branch about delay, not width. Different meanings, same root family, easy to conflate.