all-out, big, brave, determined, enormous, great, herculean, heroic, huge, major, remarkable, special, strenuous, superhuman, tremendous, valiant
She made a tremendous effort to learn the language despite her busy schedule.
desperate, frantic
The team made a desperate effort to finish the project before the deadline.
final, last, last-ditch
The team made a final effort to score before the whistle blew.
genuine, positive, real, serious
feeble
His feeble effort to fix the broken lamp just made things worse.
sporadic
The team's sporadic efforts to improve their performance finally paid off last season.
fruitless, futile, unsuccessful
collaborative, collective, concerted, cooperative, joint, team
The volunteers made a concerted effort to clean up the park before the summer festival.
conscious, deliberate
She made a deliberate effort to smile even though she was feeling sad.
voluntary
Many local schools depend on voluntary effort from parents to run after-school programs.