Please help with my homework I don't know where to find it at!?

Okay so im in 8th grade and i have language homework I have to have antonyms for the following words: hardy, cluttered, castastrophe, prudent, fruitless, vital, lax, trivial, hospitable, hilarious, lethargic, ignite, surplus, graphic, grim, despondent, hostile, lavis, and clarification! does anyone know where i can find antonyms for these words or do you know any! thanks!