enlargement vs dilation

enlargement and dilation both are nouns.

Word	Noun	Adjective	Verb	Adverb
enlargement	Yes	No	No	No
dilation	Yes	No	No	No

As nouns, dilation is a hyponym of enlargement; that is, dilation is a word with a more specific, narrower meaning than enlargement:

enlargement: the act of increasing (something) in size or volume or quantity or scope
dilation: the act of expanding an aperture

Other hyponyms of enlargement include dilatation, distension, distention, stretching, inflation, magnification, extension.

enlargement (noun)	dilation (noun)
the act of increasing (something) in size or volume or quantity or scope	the act of expanding an aperture
a photographic print that has been enlarged	a lengthy discussion (spoken or written) on a particular topic
a discussion that provides additional information
the state of being enlarged