scalage vs approximation

scalage and approximation both are nouns.

Word	Noun	Adjective	Verb	Adverb
scalage	Yes	No	No	No
approximation	Yes	No	No	No

As nouns, approximation is a hypernym of scalage; that is, approximation is a word with a broader meaning than scalage:

Other hypernyms of scalage include estimate, estimation, idea.

scalage (noun)	approximation (noun)
the act of scaling in weight or quantity or dimension	the act of bringing near or bringing together especially the cut edges of tissue
estimation of the amount of lumber in a log	the quality of coming near to identity (especially close in quantity)
	an approximate calculation of quantity or degree or worth
	an imprecise or incomplete account