verb/e.ʁi.se/
to bristle, ruffle (feathers, fur etc.); to spike; to form spikes in; to get somebody's back up
“La pluie ne tombait plus; le jour commençait à venir, et, sur les branches des pommiers sans feuilles, des oiseaux se tenaient immobiles, hérissant leurs petites plumes au vent froid du matin.” — The rain was no longer falling; the day was starting to dawn, and, on the leafless branches of the apple trees, the birds were still, ruffling their small feathers in the cold morning wind.
From Vulgar Latin *ericiare, from erīcius.