An Etymological Dictionary of Astronomy and Astrophysics

1. To make unclear or indistinct.
   

2. To fail to distinguish between; associate by mistake; confound (Dictionary.com).

Etymology (EN): Back formation from confused, M.E. confused, from O.fr. confus, from L. confusus, p.p. of confundere, → confound.

Etymology (PE): → confound.