1. [v]  become frozen and covered with glaciers
2. [v]  cover with ice or snow or a glacier; "the entire area was glaciated"

GLACIATE is a 8 letter word that starts with G.

1. \Gla"ci*ate\, v. i. [L. glaciatus, p. p. of glaciare to
   freeze, fr. glacies ice.]
   To turn to ice.
   
   

2. \Gla"ci*ate\, v. t.
   1. To convert into, or cover with, ice.
   
   2. (Geol.) To produce glacial effects upon, as in the scoring
      of rocks, transportation of loose material, etc.
   
   {Glaciated rocks}, rocks whose surfaces have been smoothed,
      furrowed, or striated, by the action of ice.