[upper limb of the human body], Middle English arm, from Old English earm, from Proto-Germanic *armaz (source also of Old Saxon, Danish, Swedish, Middle Dutch, German arm, Old Norse armr, Old Frisian erm), from PIE root *ar- "to fit together" (source also of Sanskrit irmah "arm," Greek arthron "a joint," Latin armus "shoulder").
Arm of the sea was in Old English. Arm-twister "powerful persuader" is from 1915. Arm-wrestling is from 1899.
They wenten arme in arme yfere Into the gardyn [Chaucer]
diminutive noun-forming element, Middle English, from Old French -elet, which often is a double-diminutive. It consists of Old French diminutive -et, -ette (see -et) added to nouns in -el, which in many cases represents Latin diminutive -ellus; see -el (2)). "The formation did not become common until the 18th c." [OED].
"ornamental ring or clasped chain for the wrist," mid-15c., from Old French bracelet (14c.), diminutive of bracel, from Latin bracchiale "armlet," from bracchium "an arm, a forearm," from Greek brakhion "an arm" (see brachio-).
<a href="https://www.etymonline.com/word/armlet">Etymology of armlet by etymonline</a>
Harper, D. (n.d.). Etymology of armlet. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/armlet