optimum effort (noun) best shot: all-out try
Sinonime: all, entire, exhaustive, faultless, full, full-dress, gross*, hook line and sinker, imperforate, intact, integral, integrated, lock stock and barrel, organic, outright, plenary, replete, the works, thorough, thoroughgoing, unabbreviated, unabridged, unbroken, uncensored, uncondensed, uncut, undiminished, undivided, undocked, unimpaired, unitary, unreduced, whole, whole enchilada, whole nine yards, whole-hog, whole-length