If you describe something such as an amount of money as derisory, you are emphasizing that it is so small or inadequate that it seems silly or not worth considering.
"the absurd excuse that the dog ate his homework""that's a cockeyed idea""ask a nonsensical question and get a nonsensical answer""a contribution so small as to be laughable""it is ludicrous to call a cottage a mansion""a preposterous attempt to turn back the pages of history""her conceited assumption of universal interest in her rather dull children was ridiculous"