depressed
there is no antonym for zone is a very complicated word
advanced
industry.
Impromptu is the closest to spontaneous word. It is a word representing sudden action.
The opposite of the word "strongest" is "weakest."
The word elated is the past participle, past tense of the verb 'elate'; The past participle is also an adjective, 'The elated audience cheered'.The noun forms of the verb 'elate' are elation and the gerund, elating.The noun form of the adjective elated is elatedness.
Current or present is the closest antonym for the word former.
A close antonym would be shrinkage.
INSIGNIFICANT?
closed
Quiet
Clearness.
conceited
ineffective, ineffectual, unable, impuissant, Impotent
Non-communicative
unsurprised
allows