rebracketing (aka ‘metanalysis’) is defined by wiktionary as “the process by which a word originally derived from one source is broken down or bracketed into a different set of factors”
e.g. hamburger
originally
[Hamburg] + [er](something from the German city Hamburg)
but “ham” is a known type of meat in English, so it was rebracketed
[ham] + [burger]and the new word “burger” means patty (c. 1939)
or with definite article e.g. an apron
originally
[a] + [napron](from old french diminutive of “nappe”/”tablecloth”)
but later rebracketed
[an] + [apron]and the new word “apron” usurps “napron” by the 1600s1
some other examples:
alcoholic: [alcohol] + [ic] → [alco] + [holic]
giving us -holic (addiction e.g. shopa-holic)
helicopter: [helico] + [pter] → [heli] + [copter]
giving us heli- (helicopter e.g. heli-pad)
cybernetics: [cyberne] + [tics] → [cyber] + [netics]
giving us cyber- (internet e.g. cyber-security)
for more, see wikipedia
so now it’s hard to see that ‘apron’ and ‘napkin’ are related