Brown Driver Briggs

 1. to be strong, alert, courageous, brave, stout, bold, solid, hard
  1) (Qal) to be strong, brave, bold
  2) (Piel) to strengthen, secure (for oneself), harden (heart),
make firm, make obstinate, assure
  3) (Hithpael) to be determined, to make oneself alert, strengthen
oneself, confirm oneself, persist in, prove superior to
  4) (Hiphil) to exhibit strength, be strong, feel strong