Infiltrate
/ˈɪn.fɪl.treɪt/noun
To enter or spread into something gradually, often secretly or for a covert purpose.
Did you know?Infiltrate comes from the same Latin root as words for rain and filter, so its oldest image is not espionage but liquid seeping through a barrier.
Etymological Timeline
Proto-Indo-European
PIE
*sreu-
“to flow, stream”
Latin
Latin
fluere
“to flow”
Latin
Latin
in- + filtrāre
“to strain in; to pass through or into gradually”
19th Century
English
infiltrate
“to permeate or spread into something”
Modern English
English
infiltrate
“to enter or spread into secretly or gradually”