backtick

from The Free On-line Dictionary of Computing (8 July 2008)

back quote
backtick

   <character> "`" {ASCII} code 96.  Common names: left quote;
   left single quote; open quote; {ITU-T}: grave accent; grave.
   Rare: backprime; {INTERCAL}: backspark; unapostrophe; birk;
   blugle; back tick; back glitch; push; {ITU-T}: opening single
   quotation mark; quasiquote.

   Back quote is used in {Unix} shells to invoke {command
   substitution}.

   (1996-11-26)