bend (v.) Look up bend at Dictionary.com
Old English bendan "to bend a bow; confine with a string, fetter," causative of bindan "to bind," from Proto-Germanic base *band- "string, band" (cognates: Old Norse benda "to join, strain, strive, bend"), from PIE root *bhendh- "to bind" (cognates: Gothic bindan, Old High German bintan, Sanskrit badhnati "binds," Lithuanian bendras "partner;" Old Persian bandaka- "subject").

Modern sense (early 14c.) is via notion of bending a bow to string it. Cognate with band, bind, and bond. Related: Bended; bent; bending.
bend (n.1) Look up bend at Dictionary.com
"a bending or curving," 1590s; "thing of bent shape," c.1600, from bend (v.). Earlier "act of drawing a bow" (mid-15c.). The bends "decompression pain" first attested 1894.
bend (n.2) Look up bend at Dictionary.com
"broad diagonal band in a coat-of-arms, etc.," c.1400, from earlier sense of "thin, flat strap for wrapping round," from Old English bend "fetter, shackle, chain," from PIE *bhendh- (see bend (v.)).