# filter in

CEFR C1 · Phrasal verb

Source: https://englishreference.com/word/filter-in
Updated: 2026-04-24

## Definition

to arrive or enter slowly in small groups or small amounts.

For teachers: to enter or arrive gradually, often in a scattered or piecemeal fashion; typically used for people, information, or light.

## Examples

- The crowd began to filter in just before the show started.
- Reports from the disaster zone are starting to filter in, but the full picture remains unclear.
- As the morning sun began to filter in through the heavy velvet curtains, the dusty library took on a golden, ethereal glow.

## Pitfalls

- Not "The guests filtered in the room." but "The guests filtered into the room." — when followed by a destination, use 'into'; use 'in' alone when the destination is implied or as an adverbial particle.

## Usage notes

- Usually used with plural subjects or uncountable nouns like light or information.
- Teaching tip: help students visualize a physical filter where only small amounts pass through at a time to anchor the meaning of 'gradual arrival'.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.