Source : Webster's Revised Unabridged Dictionary (1913)

Totter \Tot"ter\, v. i. [imp. & p. p. {Tottered}; p. pr. & vb.
   n. {Tottering}.] [Probably for older tolter; cf. AS.
   tealtrian to totter, vacillate. Cf.{Tilt} to incline,
   {Toddle}, {Tottle}, {Totty}.]
   1. To shake so as to threaten a fall; to vacillate; to be
      unsteady; to stagger; as,an old man totters with age. ``As
      a bowing wall shall ye be, and as a tottering fence.''
      --Ps. lxii. 3.

   2. To shake; to reel; to lean; to waver.

            Troy nods from high, and totters to her fall.
                                                  --Dryden.

Source : WordNet®

tottering
     adj 1: unsteady in gait as from infirmity or old age; "a tottering
            skeleton of a horse"; "a tottery old man" [syn: {tottery}]
     2: (of structures or institutions) having lost stability;
        failing or on the point of collapse; "a tottering empire"