hāval הָבַל ‘to become vain’ (Hebrew)

Etymology^?: a primitive root

hāval v
1) to act emptily, become vain, be vain
 1a) (Qal)
  1a1) to become vain
  1a2) to be utterly vain (with cognate acc)
 1b) (Hiphil)
  1b1) to cause to become vain
  1b2) to fill with vain hopes