A machine that inserts components into envelopes for mass mailing(noun)
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Use "inserter" in a sentence
"I've never tried the inserter, which is sort of creepy-looking, because I like being able to manually adjust the angle to better fit different body parts (so, less of an angle on the thigh, a large one for the hips/butt, etc.)."
"In another, less generous, passage she imagines him as a murderer, a "serial bronchoscopist . . . a slitter of throats and inserter of cold rods"."
"Women's sexual relationships lacked a dominant inserter and subordinate receiver and were, thus, an unnatural disorder."