“Yield not to misfortunes” or “Do not give in to evil” is a rough translation. Tu ne cede malis sed contra audentior ito comes from Virgil's Aeneid, Book VI; this means “do not give in to evil but proceed ever more boldly against it”. A hand is holding a leafy branch (an oak branch if it is indeed the Williams' family crest, as we suspect.) Also, it's the motto of the Bronx!