Where does “hymynhäive” come from?

hymynhäive (Finnish) comes from Finnish häive, from Finnish häipyä, from Finnish haipua, from Finnish -pua — Forms passive verbs.

Ancestry of “hymynhäive”, step by step

hymynhäive traces back through two separate lines of ancestry.

via Finnish häive

StepLanguageWordMeaning
1Finnishhäiveglimpse, hint, trace
2Finnishhäipyäto disappear, vanish visibly of something visible: to gradually get less visible or clear
3Finnishhaipuato fade away
4Finnish-puaForms passive verbs

via Finnish hymy

StepLanguageWordMeaning
1Finnishhymysmile
Every word from Finnish -pua →Every word from Finnish haipua →Every word from Finnish häipyä →