Gumption
Etymology
First recorded in Scots English in the early 1700s, meaning "common sense, shrewdness." Its deeper origin is obscure, with no agreed source. The "initiative, drive" sense grew alongside the "good sense" one, so today gumption carries both: brains and the push to use them.
noun · /GUMP-shun/
Practical good sense combined with the initiative to actually do something.
What it names
A single word for the blend of common sense and get-up-and-go — the quality of the person who sees what needs doing and just starts.
Example
Nobody told her to fix the broken intake form; she just had the gumption to rebuild it over a weekend.
Related idea
Moxie is closer to sheer nerve; gumption always keeps a foot in practicality and level-headedness.