: having unwanted elements (such as sediments) removed by means of a filter: subjected to filtration
filtered water
2
: made less intense, full, or pure by being partially blocked
plants that do well in filtered sunlight
Adjustable slats (vanes) fit between sheets of polyester fabric, allowing a filtered view or complete privacy. Daniel Gregory
Frantic July tourist cars sent up a filtered sound and smell through the tall plane trees below the windows. M. F. K. Fisher
3
: having a filter
filtered cigarettes
A few days or perhaps weeks later, the person moves into one of the big, specially filtered rooms and starts the chemotherapy, which is tenderly called ablation. Sallie Tisdale