The Collaborative International Dictionary of English v.0.48:

Sierra \Si*er"ra\, n. [Sp., properly, a saw, fr. L. serra a saw.
   See Serrate.]
   A ridge of mountain and craggy rocks, with a serrated or
   irregular outline; as, the Sierra Nevada.
   [1913 Webster]

         The wild sierra overhead.                --Whitter.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sierra
    n 1: a range of mountains (usually with jagged peaks and
         irregular outline)
    2: a Spanish mackerel of western North America [syn: sierra,
       Scomberomorus sierra]

The Free On-line Dictionary of Computing (19 January 2023):

Sierra

    (Or "Sierra On-Line") A computer game
   developer founded in the early 1980s by Ken and Roberta
   Willams in the small mountain town of Oakhurst California.
   Sierra was named after the local mountian range, 15 miles from
   the famous Yosemite National Park.

   In 1997 Sierra was purchased by CUC and its main office is
   now in Seattle, WA, USA.

   Products include Kings Quest, Space Quest, Police Quest, Quest
   for Glory, Robin Hood, Phantasmagoria, Leisure Suit Larry, Eco
   Quest and many more.

   (http://sierra.com /).

   (1997-11-23)