Meaning: Taint is something that corrupts or makes something undesirable.
Taint means to affect with something physically injurious, unpleasant, infect, poison etc.
Example: Water supply has been tainted with arsenic.
Synonyms: Blemish, Contamination, Corruption, Defect
Antonyms:Benefit, Advantage, Honor, Perfection

Meaning: Wane is defined as a period of decline in size or intensity.
Example: After eight in the night, the crowd began to wane.
Synonyms:Decrease, Atrophy, Abate, Diminish
Antonyms: Brighten, Develop, Enhance, Enlarge

Meaning: A zealot is someone who is fanatical about a belief.
Example: Zealots on the both sides of the political issue started fighting.
ynonyms: Enthusiast, Activist, Extremist, Fanatic
Antonyms: Conservative, Moderate

Meaning: Craven is someone who is an abject coward, fearful person.
Example: The craven fellow turned and ran away.
Synonyms: Cowardly, Gutless, Dastardly, Unheroic
Antonyms: Brave, Courageous, Doughty, Fearless

Meaning: Something that is corresponding to what is right, proper, or reasonable; suitable; appropriate.
Example: worked because it sounded so congruous, so sensible.
Synonyms:Corresponding, Suitable, Congruent, Appropriate
Antonyms: Incongruous, Disagreeing, Unfitting, Unsuitable