filter
濾 centers on passing a liquid or substance through a porous material to separate out unwanted parts: filtering, straining, or percolating.
濾 combines 氵 (water) with 慮, which likely contributes the sound and the idea of careful consideration, suggesting the careful separation of water from impurities.
Water 氵 passes through the thoughtful, careful structure of 慮, like a mind sifting through thoughts. Imagine pouring water through a fine mesh that only lets the purest drops through.
For ロ, picture a low, slow pour through a filter: low -> ロ, and the water drips down carefully.
filtration; filtering; percolation
Graafian follicle
parafollicular cell
filter press
cloth strainer; filter cloth
filtrand; filter residue; residue
filtered water
filter bed
water filter
filtrate
follicle (esp. an ovarian follicle)
strainer; colander; filter
virus
unfiltered (alcohol)
glaucoma filtration surgery
ultrafiltration