let \let\, v. i.
   1. to forbear. obs. --bacon.
      1913 webster

   2. to be let or leased; as, the farm lets for $500 a year.
      see note under let, v. t.
      1913 webster

   to let on, to tell; to tattle; to divulge something. low
      

   to let up, to become less severe; to diminish; to cease;
      as, when the storm lets up. colloq.
      1913 webster
see also:
let to let on to let up