Meaning

noun the distance by which one thing clears another; the space between them

noun vertical space available to allow easy passage under something

noun permission to proceed

originEtymology tree English clear Proto-Indo-European *-yós Proto-Italic *-ios Old Latin -ios Latin -ius Latin -iader. Old French -ancebor. Middle English -aunce English -ance English clearance From clear + -ance.

Etymology from Wiktionary, CC BY-SA 3.0