The story
- Old English · inherited frominsendan“to send in, put in”
- Middle English · inherited frominsenden
- English todayinsend
From Middle English insenden, from Old English insendan (“to send in, put in”), equivalent to in- + send. Cognate with Dutch inzenden (“to send in, put in”), German einsenden (“to send in, submit”).
Etymology from Wiktionary, CC BY-SA 4.0.