appal vs shock

appal is not a noun while shock is a noun.

Word	Noun	Adjective	Verb	Adverb
appal	No	No	Yes	No
shock	Yes	No	Yes	No

As verbs, appal and shock are synonyms defined as:

Other synonyms of appal include appall, offend, outrage, scandalise, scandalize.

As verbs, shock is a hyponym of appal; that is, shock is a word with a more specific, narrower meaning than appal:

appal (noun)	shock (noun)
	a reflex response to the passage of electric current through the body
	the violent interaction of individuals or groups entering into combat
	a mechanical damper; absorbs energy of sudden impulses
	an instance of agitation of the earth's crust
	an unpleasant or disappointing surprise
	a sudden jarring impact
	the feeling of distress and disbelief that you have when something bad happens accidentally
	a pile of sheaves of grain set on end in a field to dry; stalks of Indian corn set up in a field
	a bushy thick mass (especially hair)
	(pathology) bodily collapse or near collapse caused by inadequate oxygen delivery to the cells; characterized by reduced cardiac output and rapid heartbeat and circulatory insufficiency and pallor

appal (verb)	shock (verb)
strike with disgust or revulsion	inflict a trauma upon
fill with apprehension or alarm; cause to be unpleasantly surprised	subject to electrical shocks
	collect or gather into shocks
	collide violently
	strike with horror or terror
	surprise greatly; knock someone's socks off
	strike with disgust or revulsion