ensayar
rehearse
essay
a short piece of writing
+
-ar
verb suffix
Ensayar means to rehearse and can be thought of as essay0 + -ar1. Just as you might practice writing0 an essay, you rehearse (practice) a performance.
verb
  1. rehearse
    To rehearse or practice a performance
    Los actores ensayan la obra de teatro. // The actors rehearse the play.
  2. try on
    To try on clothing or accessories
    Voy a ensayar este vestido. // I'm going to try on this dress.