The Collaborative International Dictionary of English v.0.48:

Desideratum \De*sid`e*ra"tum\, n.; pl. Desiderata. [L., fr.
   desideratus, p. p. See Desiderate.]
   Anything desired; that of which the lack is felt; a want
   generally felt and acknowledge. Desidiose

The Collaborative International Dictionary of English v.0.48:

Desiderata \De*sid`e*ra"ta\, n. pl.
   See Desideratum.
   [1913 Webster]