the.com/shudder
the body's full-frame flinch when fear or disgust skips the brain entirely
means to tremble or shake convulsively, usually from fear, cold, or revulsion
from From Middle English shoddren or schoderen, and a cousin of Middle Dutch and Low German shudderen — all of them likely echoing an older Germanic root meaning to shake or quiver. The doubled-d gives the word its own physical tremor, the kind that rattles out of you before you've decided to feel anything at all.
reflex rootShares circuitry with the shiver that warms you
goosebumps kinTiny muscles fluffing hairs you no longer have
phantom originEcho of mammals making fur look bigger
the wordFrom Middle English meaning to tremble with cold
contagiousWatching someone shudder can trigger your own