濾

A phono-semantic compound consisting of:

水 (water) — semantic component, indicates relation to liquids;

慮 — phonetic component, supplying the sound (려 / lǜ).

Originally, it described filtering water or liquid substances.

Semantic development:

- to strain liquid;

- to purify by removing impurities;

- to screen or filter (figurative use).

The metaphorical extension applies to information filtering or selective thinking.

Used mainly in scientific and technical vocabulary (chemistry, biology, engineering).

여과 (濾過) — filtration

여지 (濾紙) — filter paper

여액 (濾液) — filtrate

濾 emphasizes removal of impurities through a filtering process.

Related characters:

慮 — to consider; to deliberate (phonetic base)

過 — to pass; to go through

淨 — pure; clean

清 — clear