掠 has two main senses: violent (掠夺 plunder, 掠取 seize) and swift motion (掠过 skim past). In literary Chinese, it conveys speed and lightness of movement.
扌 is the left-side form of 手 (hand). It marks 掠 as a physical action - to seize, plunder or sweep past with the hand - and groups it with other hand-action chars like 抢, 拿, 抱.
京 jīng provides the sound, shifted to lüè by an old initial change. The same phonetic feeds 凉 (liáng, cool), 谅 (liàng, forgive) and 晾 (liàng, dry), so the liáng/lüè branch is a recurring l- side of the 京 family.