Sill

[ sil ]
/ sɪl /

noun

Mount, a mountain in E central California, in the Sierra Nevada Mountains. 14,153 feet (4314 meters).
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for mount-sill

sill

/ (sɪl) /

noun

a shelf at the bottom of a window inside a room
a horizontal piece along the outside lower member of a window, that throws water clear of the wall below
the lower horizontal member of a window or door frame
a continuous horizontal member placed on top of a foundation wall in order to carry a timber framework
a flat usually horizontal mass of igneous rock, situated between two layers of older sedimentary rock, that was formed by an intrusion of magma

Word Origin for sill

Old English syll; related to Old Norse svill sill, Icelandic svoli tree trunk, Old High German swella sill, Latin solum ground
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for mount-sill

sill

[ sĭl ]

A sheet of igneous rock intruded between layers of older rock. See illustration at batholith.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.