Where does “þūmô” come from?

þūmô (Proto-Germanic) comes from Proto-Indo-European tūm-, from Proto-Indo-European tewh₂- — to swell; to crowd; to be strong.

þūmô (Proto-Germanic): thumb

Definitions

Step	Language	Word	Meaning
1	Proto-Indo-European	tūm-	to grow; to swell, to increase; to swell, be...
2	Proto-Indo-European	tewh₂-	to swell; to crowd; to be strong

þūmô — Etymology, Origin & Word History | Etymology Explorer