Where does “pikkukieli” come from?

pikkukieli (Finnish) comes from Finnish kieli, from Proto-Finnic keeli, from Proto-Uralic käle — tongue; language.

Ancestry of “pikkukieli”, step by step

pikkukieli traces back through two separate lines of ancestry.

via Finnish kieli

StepLanguageWordMeaning
1Finnishkielitongue; language; string
2Proto-Finnickeelitongue; language
3Proto-Uralickäletongue; language

via Finnish pikku

StepLanguageWordMeaning
1Finnishpikkulittle, small; little old
2Finnishpienilittle, small; Third-person singular indicative...
3Proto-Finnicpeenilittle, small; fine
Every word from Proto-Uralic käle