skeleton vs lower limit

skeleton and lower limit both are nouns.

Word	Noun	Adjective	Verb	Adverb
skeleton	Yes	No	No	No
lower limit	Yes	No	No	No

As nouns, lower limit is a hypernym of skeleton; that is, lower limit is a word with a broader meaning than skeleton:

Other hypernyms of skeleton include minimum.

skeleton (noun)	lower limit (noun)
the internal supporting structure that gives an artifact its shape	the limit on the lower (or southernmost) side of something
the hard structure (bones and cartilages) that provides a frame for the body of an animal	the smallest possible quantity
a scandal that is kept secret
something reduced to its minimal form