out
1.
to remove sth that you do not want from a liquid, light, etc. by using a special device or substance :
to filter out dust particles / light / impurities
2.
to remove sb/sth that you do not want from a large number of people or things using a special system, device, etc. :
The test is used to filter out candidates who may be unsuitable.
The software filters out Internet sites whose content is not suitable for children.