The Collaborative International Dictionary of English v.0.48:

Knoll \Knoll\, v. i.
   To sound, as a bell; to knell. --Shak.
   [1913 Webster]

         For a departed being's soul
         The death hymn peals, and the hollow bells knoll.
                                                  --Byron.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Knoll \Knoll\, n.
   The tolling of a bell; a knell. [R.] --Byron.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Knoll \Knoll\ (n[=o]l), n. [AS. cnoll; akin to G. knolle,
   knollen, clod, lump, knob, bunch, OD. knolle ball, bunch, Sw.
   kn["o]l, Dan. knold.]
   A little round hill; a mound; a small elevation of earth; the
   top or crown of a hill.
   [1913 Webster]

         On knoll or hillock rears his crest,
         Lonely and huge, the giant oak.          --Sir W.
                                                  Scott.
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The Collaborative International Dictionary of English v.0.48:

Knoll \Knoll\, v. t. [imp. & p. p. Knolled; p. pr. & vb. n.
   Knolling.] [OE. knollen, AS. cnyllan. See Knell.]
   To ring, as a bell; to strike a knell upon; to toll; to
   proclaim, or summon, by ringing. "Knolled to church." --Shak.
   [1913 Webster]

         Heavy clocks knolling the drowsy hours.  --Tennyson.
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WordNet (r) 3.0 (2006):

knoll
    n 1: a small natural hill [syn: knoll, mound, hillock,
         hummock, hammock]

Moby Thesaurus II by Grady Ward, 1.0:

36 Moby Thesaurus words for "knoll":
   anthill, barrow, brae, butte, crest, down, drumlin, dune,
   elevation, fell, foothills, hill, hillock, hilltop, hummock, knob,
   lofty peak, molehill, monticle, monticule, moor, mound,
   mountaintop, peak, pic, pico, pike, pinnacle, point, precipice,
   rise, sand dune, spur, summit, swell, tor