vb, -trat*ed  -trat*ing vt  1  :  to cause (as a liquid) to permeate something by penetrating its pores or interstices < tissue with a local anesthetic>   2  :  to pass into or through (a substance) by filtering or permeating vi  :  to enter, permeate, or pass through a substance or area by filtering
, n :  something that passes or is caused to pass into or through something by permeating or filtering : esp  :  a substance that passes into the bodily tissues and forms an abnormal accumulation <a lung >  .
 
   
 
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