fright vs shudder

fright and shudder both are nouns.

Word	Noun	Adjective	Verb	Adverb
fright	Yes	No	Yes	No
shudder	Yes	No	Yes	No

As nouns, shudder is a hyponym of fright; that is, shudder is a word with a more specific, narrower meaning than fright:

fright: an emotion experienced in anticipation of some specific pain or danger (usually accompanied by a desire to flee or fight)
shudder: an almost pleasurable sensation of fright

fright (noun)	shudder (noun)
an emotion experienced in anticipation of some specific pain or danger (usually accompanied by a desire to flee or fight)	an involuntary vibration (as if from illness or fear)
	an almost pleasurable sensation of fright

fright (verb)	shudder (verb)
cause fear in	shake, as from cold
	tremble convulsively, as from fear or excitement