Meaning of nil desperandum*

nil de•spe•ran•dum

Pronunciation: (nēl' des"pe-rän'doom Eng. nil' des"p&schwa-ran'd&schwam), [key]
— Latin. Latin.
  1. never despair.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.