desesperar
despair
des-
negative prefix
+
esperar
to hope
Desesperar means to despair and can be thought of as des-0 (negative prefix0) + esperar1 (to hope1), literally meaning 'to un-hope' or 'to lose hope'.
verb
  1. despair
    To lose hope or become extremely worried or upset
    No desesperes, encontraremos una solución. // Don't despair, we'll find a solution.