noun
leg trip
A technique in sumo, judo, and other martial arts where one sweeps or hooks the opponent's leg to unbalance them.
彼は足掛けで相手を倒した。
He tripped his opponent with a leg hook.
岩に足掛けを見つけて登った。
I found a foothold on the rock and climbed up.
ミシンの足掛けを踏んで動かす。
You operate the sewing machine by pressing the pedal.
noun, used as a prefix
spanning (years, months, etc.)
Used as a prefix to indicate a period that spans across calendar units, counting partial start and end units as full ones. Common in expressions like 足掛け3年 (spanning three calendar years).
このプロジェクトは足掛け3年にわたった。
This project spanned three calendar years.
足場 refers to a scaffolding or a secure place to stand, often in construction or climbing. 足掛け is a smaller, more specific foothold or a pedal.
Compound of 足 (foot) and 掛け (hanging, hooking), from the verb 掛ける. The sumo sense directly reflects the action of hooking a leg. The spanning sense is a figurative extension, treating time as something one steps across.