Where does “-kku” come from?

-kku (Finnish) comes from Finnish -kkä, from Finnish -inen, from Finnish -uus, from Proto-Finnic -uc — -ness, -hood.

Ancestry of “-kku”, step by step

StepLanguageWordMeaning
1Finnish-kkäFront vowel variant of -kka
2Finnish-inen-like, -ous, -y; -en; Creates adjectives from...
3Finnish-uusForms nouns from adjectives, expressing a quality
4Proto-Finnic-uc-ness, -hood

Words derived from “-kku”

Every word from Proto-Finnic -uc →Every word from Finnish -inen →Every word from Finnish -uus →