pauldron
A component of plate armor that protects the shoulder, generally covering more than a spaulder, also protecting the armpit and overlapping with other armor over the upper chest and back.
historical
Upon the espaulieres are placed pauldrons, also ridged, with the edges turned up, so as to form the prototypes of pass-guards.
Where it comes from
From earlier pouldron, poleron, paleron from Middle English polron, palerns, pollerons. This may have been borrowed from Old French paleron, which derives from elements corresponding to French pale (“blade (of a shovel, etc)”) + -eron but was semantically influenced by Old French espaule (“shoulder”) (whence French épaule). Alternatively, some references derive the Middle English word from Middle French espalleron, espauleron, from Old French espaule. Although a form with d at the end is found in Middle English (polrondys, compare Early Modern English polrynges c. 1550), the interpolation of a d between the l and the r dates to the 1500s; the d, and the preference since the early 1800s for the spelling and pronunciation with paul- rather than poul-, may be due to the influence of spaulder.
Adapted from the Wiktionary entry pauldron (CC BY-SA 4.0).