one who knows an epoch, age

discerning, penetrating, quick of apprehension, perspicacious

one who knows the worth of

knowing, acquainted with, intelligence, explanation, notification, identity, knowledge

intelligent, sharp-minded

one who appreciates loyalty, faithfulness, sincerity

duty-conscious

diplomat, opportunist, tactful

physiognomist, scientist of physiognomy

one who recognizes human worth

one who understands signs and gestures

acquainted with river, swimmer

acquainted with humanity, the one who know the human nature, the one who knows the good and bad nature of human, the one who appreciating the good guy

the one who know the people, the one who have knowledge about people behavior and character

a palmist, astrologer

grateful, thankful, obliged, oblige

an opportunist

who feels the pulse, a knower

A philologist, lexicographer,linguistics.

one who recognizes signs, understands hints, knower of secrets

the one who well acquainted with the nature of the woman, the one who is aware about qualities of a woman

knowing and performing (one's) duty, one who renders to everyone his due, knowing what is right, pious, grateful

godly, pious, god knowing, mystic, one who recognizes the God

pathologist

a person who knows his/her aim or destination, the one who know about difficulties, the one who reaches reality

(about art and education) consciousness, percipient

self-aware, enlightened

Ornithologist.

one who is not acquainted with vale or worth

time/ age

constancy of unacquainted, faithless, inconsiderate, treacherous

movement of world, times

unique, rare one of the times

calamities of time