Where does “underextension” come from?

underextension (English) comes from English Extension, from Middle English extensioun, from Old French estension, from Latin extensio, from Latin -tiō, from Latin dissertātiō, from Latin dissertus, from Latin disserere — small stone, pebble; gravel, rubble.

underextension (English): Application of a term to too few referents, as...

Definitions

  1. Application of a term to too few referents, as...

Ancestry of “underextension”, step by step

underextension traces back through two separate lines of ancestry.

via English Extension

StepLanguageWordMeaning
1EnglishExtensionThe act of extending; a stretching out; enlargement in length, breadth, or time; an increase
2Middle Englishextensioun
3Old Frenchestension
4Latinextensioextension, stretching; swelling, tumour
5Latin-tiōtion, -ation, -ing
6Latindissertātiō(spoken) dissertation, discourse, disquisition
7Latindissertusarranged, disposed; explained
8Latindissereresecond-person singular future passive indicative...
9Latindis-asunder, apart, in two; reversal, removal;...
10Latincalceusshoe
11Latincalxlimestone; chalk; the finish line
12Ancient Greekχάλιξsmall stone, pebble; gravel, rubble

via English under

StepLanguageWordMeaning
1EnglishunderIn or at a lower level than; As a subject of;...
2Middle Englishunderunder
3Old Englishunderunder, beneath
4Proto-Germanicunderamong, between; under, beneath; under
5Proto-Indo-Europeanh₁entérbetween
6Proto-Indo-Europeanh₁enin; in, inside
Every word from Ancient Greek χάλιξEvery word from Latin -tiōEvery word from Latin dis-