Where does “pentukoira” come from?

pentukoira (Finnish) comes from Finnish koira, from Finnish -nen, from Finnish -inen, from Finnish -uus, from Proto-Finnic -uc — -ness, -hood.

Ancestry of “pentukoira”, step by step

pentukoira traces back through two separate lines of ancestry.

via Finnish koira

StepLanguageWordMeaning
1Finnishkoiradog; dog paddle; military police
2Finnish-nenForms diminutives nouns or terms expressing...
3Finnish-inen-like, -ous, -y; -en; Creates adjectives from...
4Finnish-uusForms nouns from adjectives, expressing a quality
5Proto-Finnic-uc-ness, -hood

via Finnish pentu

StepLanguageWordMeaning
1Finnishpentucub, puppy; kid
2Finnishpenidog
3Proto-Finno-Ugric*peni
4Proto-Uralicpenädog
Every word from Proto-Finnic -uc