Where does “ehkäisyvaahto” come from?

ehkäisyvaahto (Finnish) comes from Finnish vaahto, from Proto-Finnic vakto, from Proto-Germanic þwahtuz, from Proto-Germanic -þuz, from Proto-Indo-European -tus — Derives action nouns from verb roots.

ehkäisyvaahto (Finnish): contraceptive foam

Definitions

contraceptive foam

Ancestry of “ehkäisyvaahto”, step by step

ehkäisyvaahto traces back through two separate lines of ancestry.

via Finnish vaahto

Step	Language	Word	Meaning
1	Finnish	vaahto	foam; head; mousse
2	Proto-Finnic	vakto	foam
3	Proto-Germanic	þwahtuz	washing, laundry
4	Proto-Germanic	-þuz	Forms result nouns from verb roots, usually from...
5	Proto-Indo-European	-tus	Derives action nouns from verb roots

via Finnish ehkäisy

Step	Language	Word	Meaning
1	Finnish	ehkäisy	prevention; contraception; When used as modifier...
2	Finnish	ehkäistä	To prevent, keep from occurring, avert, block,...
3	Finnish	ehkä	perhaps, maybe; although, though
4	Proto-Finnic	ehkä	perhaps, maybe

Every word from Proto-Indo-European -tus →Every word from Proto-Germanic -þuz →Every word from Proto-Germanic þwahtuz →