Yes, it is the past tense of the verb "to disappear." It may be used as an adjective.
"Had" is a verb. It is the past tense of the verb "have."
Examples of words ending in -tch with their corresponding parts of speech:batch = verb, nounblotch = verb, nouncatch = verb, nounclutch = verb, noun, adjectivecrutch = nounditch = verb, nounDutch = noun, adjectivedutch = adverbfetch = verb, nounglitch = verb, nounhatch = verb, nounhutch = nounitch = verb, nounlatch = verb, nounmatch = verb, nounpatch = verb, nounpitch = verb, nounscratch = verb, noun, adjectivesketch = verb, nounstitch = verb, nounstretch = verb, noun, adjectiveswitch = verb, nounthatch = verb, nountwitch = verb, nounwatch = verb, nounwitch = verb, noun
The verb 'be' can function as both a linking verb and a helping verb. As a linking verb, it connects the subject with a subject complement that describes or renames it. As a helping verb, 'be' is used in progressive tenses and passive voice constructions to indicate the tense of the main verb.
verb
Helping verb.
the boats that dissapeared in the Bermuda triangle i do not know but there were a couple of boats and ships
They dissapeared
They dissapeared
she dissapeared
the Aztecs dissapeared in 1518
Someone stole it?
nobody really knows
It dissapeared.
Sunset.
Jamestown, virginia
dissapeared
cobblers had nearly dissapeared