transcription, транскрипция: [ noun ]
also lynch·pin ˈlinch-ˌpin
Etymology: Middle English lynspin, from lyns linchpin (from Old English lynis ) + pin; akin to Middle High German luns linchpin
Date: 13th century
1. : a locking pin inserted crosswise (as through the end of an axle or shaft)
2. : one that serves to hold together parts or elements that exist or function as a unit
the linchpin in the defense's case