This brand of cigarette uses an active charcoal filter.
Mary put a filter on her sink faucet to remove trace elements from the tap water.
The winemaker used no filters during the fermentation process.
WordNet 3.0 Sense Numbers: 1
The engineer ran the signal through a low-pass filter.
This headset has a noise-reduction filter.
WordNet 3.0 Sense Numbers: 2
The photographer used a blue filter and a fast exposure for this picture.
John put a special filter over the lens of his telescope in order to look at the sun.
The clouds act as a filter and block certain wavelengths of sunlight.
WordNet 0.0 Sense Numbers: 1b