filter in WordNet English dictionary

1. run or flow slowly, as in drops or in an unsteady stream
   "water trickled onto the lawn from the broken hose"; "reports began to dribble in"
   trickle  dribble  filter 
   
2. remove by passing through a filter
   "filter out the impurities"
   filter  filtrate  strain  separate out  filter out 
   
3. pass through
   "Water permeates sand easily"
   percolate  sink in  permeate  filter 
   

1. device that removes something from whatever passes through it
   filter 
   
2. an electrical device that alters the frequency spectrum of signals passing through it
   filter