The Collaborative International Dictionary of English v.0.48:

Approach \Ap*proach"\, v. i. [imp. & p. p. Approached; p. pr.
   & vb. n. Approaching.] [OE. approchen, aprochen, OF.
   approcher, LL. appropriare, fr. L. ad + propiare to draw
   near, prope near.]
   1. To come or go near, in place or time; to draw nigh; to
      advance nearer.
      [1913 Webster]

            Wherefore approached ye so nigh unto the city? --2
                                                  Sam. xi. 20.
      [1913 Webster]

            But exhorting one another; and so much the more, as
            ye see the day approaching.           --Heb. x. 25.
      [1913 Webster]

   2. To draw near, in a figurative sense; to make advances; to
      approximate; as, he approaches to the character of the
      ablest statesman.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Approaching \Ap*proach"ing\, n. (Hort.)
   The act of ingrafting a sprig or shoot of one tree into
   another, without cutting it from the parent stock; -- called,
   also, inarching and grafting by approach.
   [1913 Webster]

WordNet (r) 3.0 (2006):

approaching
    adj 1: of the relatively near future; "the approaching
           election"; "this coming Thursday"; "the forthcoming
           holidays"; "the upcoming spring fashions" [syn:
           approaching, coming(a), forthcoming, upcoming]
    n 1: the event of one object coming closer to another [syn:
         approach, approaching]
    2: the temporal property of becoming nearer in time; "the
       approach of winter" [syn: approach, approaching,
       coming]
    3: the act of drawing spatially closer to something; "the
       hunter's approach scattered the geese" [syn: approach,
       approaching, coming]

Moby Thesaurus II by Grady Ward, 1.0:

108 Moby Thesaurus words for "approaching":
   about to be, advancing, already in sight, approximate,
   approximating, approximative, arm-in-arm, arriving, asymptotic,
   at hand, attracted to, brewing, burning, centripetal, centrolineal,
   cheek-by-jowl, close, close at hand, coming, concurrent, confluent,
   confocal, connivent, converging, desired, destinal, destined,
   determined, drawn to, emergent, entering, eventual, extrapolated,
   fatal, fated, fatidic, focal, forthcoming, future, futuristic,
   gathering, going to happen, hand-in-hand, hereafter, homeward,
   homeward-bound, hoped-for, hot, immediate, imminent, impendent,
   impending, in danger imminent, in prospect, in reserve, in store,
   in the cards, in the offing, in the wind, in view, inbound,
   incoming, instant, intimate, inward-bound, later, looming,
   lowering, lurking, meeting, menacing, mutually approaching, near,
   near at hand, near the mark, nearing, nearish, nigh, nighish,
   on the horizon, oncoming, overhanging, planned, plotted, predicted,
   preparing, probable, projected, prophesied, propinque, prospective,
   proximal, proximate, radial, radiating, side-by-side, tangent,
   tangential, that will be, threatening, to come, to-be, ultimate,
   uniting, upcoming, vicinal, waiting, warm