Zirak is a Khuzdul word, appearing in Zirakzigil ("tine of silver").
The word also appears as a short form of Zirakzigil, the Dwarves' name for the mountain called Celebdil or Silvertine by other races.
As zigil apparently means "silver", Zirak presumably means "tine" in Khuzdul.
<ref> tags exist, but no
<references/> tag was found