Pusillanimity
Etymology
From Late Latin pusillanimitas, from pusillanimis, "faint-hearted," which joins pusillus, "very small, petty" (a diminutive of pusus, "boy"), with animus, "spirit." It is the exact opposite of magnanimity: where that word means a great soul, this names a shrunken one — a spirit too small to rise to the moment.
noun · /pyoo-sih-luh-NIM-ih-tee/
Faint-hearted timidity — a smallness of spirit that shrinks from difficulty, risk, or responsibility.
What it names
The failing of the person who lacks the nerve to act boldly or take a stand, retreating into caution out of cowardice rather than wisdom.
Example
It was pure pusillanimity that kept the committee silent while a colleague was blamed for a mistake they all knew he had not made.
Related idea
Cowardice is failure of nerve in the face of danger or pain; pusillanimity is broader and more characterological — a habitual smallness of spirit, timid even where no real threat exists.