Where does “bethumb” come from?

bethumb (English) comes from English thumb, from Middle English þombe, from Old English þūma, from Proto-West Germanic þūmō, from Proto-Germanic þūmô, from Proto-Indo-European tūm-, from Proto-Indo-European tewh₂- — to swell; to crowd; to be strong.

bethumb (English): To take hold of or mark with the thumbs; soil or...

Definitions

  1. To take hold of or mark with the thumbs; soil or...

Ancestry of “bethumb”, step by step

bethumb traces back through two separate lines of ancestry.

via English thumb

StepLanguageWordMeaning
1EnglishthumbThe short thick digit of the hand that for humans...
2Middle Englishþombethumb; thumb-length; big toe
3Old Englishþūmathumb
4Proto-West Germanicþūmōthumb
5Proto-Germanicþūmôthumb
6Proto-Indo-Europeantūm-to grow; to swell, to increase; to swell, be...
7Proto-Indo-Europeantewh₂-to swell; to crowd; to be strong

via English Be

StepLanguageWordMeaning
1EnglishBeAs an auxiliary verb
2Middle EnglishbeAlternative form of been; Alternative form of...
3Old EnglishbēoI become, I will be, I am; bee
4Proto-Germanicbiumifirst-person singular present active indicative...
5Proto-Germanic*beuną
6Proto-Indo-Europeanbʰew-to grow, swell; to swell, wax, grow; to blow; to...
Every word from Proto-Indo-European tewh₂-Every word from Proto-Indo-European tūm-Every word from Proto-Germanic þūmô