One Word Substitution

All Important One Word Substitution related to generic terms.
A complete inability to speak is alalia
One who believes in fate is fatalist

Collective nouns
bench of magistrates/judges
bunch/posy/cluster of grapes
bunting of flags
complex of psychologists

Root word form the basis of new words by adding prefix or suffix. Idea of root word can be little helpful in guessing meaning of unknown.
Ambi means both
ambivalent – one who has contradictory view
ambidextrous – one who can use both hands efficiently
ambiguous – statement which is contradictory to itself
ambivert – one who has both extrovert and introvert personality traits