The Collaborative International Dictionary of English v.0.48:

Shimmer \Shim"mer\, v. i. [imp. & p. p. Shimmered; p. pr. &
   vb. n. Shimmering.] [OE. schimeren, AS. scimerian; akin to
   sc[imac]mian, sc[imac]man, to glitter, D. schemeren, G.
   schimmern, Dan. skimre, Sw. skimra, AS. sc[imac]ma a light,
   brightness, Icel. sk[imac]ma, Goth. skeima a torch, a
   lantern, and E. shine. [root]157. See Shine, v. i.]
   To shine with a tremulous or intermittent light; to shine
   faintly; to gleam; to glisten; to glimmer.
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         The shimmering glimpses of a stream.     --Tennyson.
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