1) Contended 2) Endeavored 3) Exerted much effort 4) Fought 5) Labored 6) Made a concerted effort 7) Made a real effort 8) Made a valiant effort 9) Made an effort 10) Moved heaven and earth 11) Put in effort 12) Spared no effort 13) Took pains 14) Tried hard 15) Tried mightily 16) Tried very hard 17) Went all-out Found on https://www.crosswordclues.com/clue/strove