What's the difference between i.e. and e.g.?
1590s, formed from dilate on the mistaken assumption that the -ate in that word was the Latin verbal suffix (it is instead part of the stem); the proper form, dilatation, is older (c.1400).
dilation di·la·tion (dī-lā'shən, dĭ-)n.
The act of expanding or the condition of being expanded.