One word Substitution 

• One who loves mankind- Philanthropist 
• One who hates mankind- Misanthropist
• One who loves language- Philologist 
• One who hates language- Misologist
• One who loves marriage- Philogamist
• One who hates marriage - Misogamist
• One who distrusts and dislikes everybody- Misocapnic
• One who beliefs easily- Credulous
• One who is violently hostile to establish beliefs, customs, traditions, institutions - Iconoclast
• One who is easily fooled- Gullible
• One who is able to talk very quickly- Volluble
• One who collects postage stamps- Philatelish
• One who collected coins- Numismatist
• One who flirts with women- Philanderer
• a man known for seducing women and having many lovers- Casanova
• One who flirts with men - Paramour
• One who does not marry especially for the religious obligation- Celibate
• One who retires from society to live a solitary life- Recluse
• One who is citizen of the world- Cosmopolitan 
• One who eats human flesh- Cannibal
• One who eats flesh- Carnivorous 
• One who abstains from alcoholic drinks and restrict others to take so- Tee-totaller
• One who is indifferent to pain and pleasure- Stoic
• All type of excitement- Stolid
• One who believes in God- Theist
• One who does not belive in God- Atheist 
• One who believes that God exists every object of nature- Pantheist
• One who does not believe in God of anything except material things- Agnistic 
• One who displays one's knowledge- Pedant
• A person having the same name as another- Namesake
• A person living in the same time as another- Contemporary 
• One who is very talkative - Garrulous/ Loquacious 
• One who is habitually silent- Taciturn/ Reticent
• One who cuts precious stones- Lapidist 
• One who deals in cattle- Drover
• One who takes delights in excessive cruelty- Sadist
• A person who helps you to break the law- Accomplice
• A man who starves body for the good of soul- Ascetic
• Women trained to help other woman in child birth- Midwife
• A person with full of discretionary powers to act on behalf of a country- Plenipotentiary 
• A pioneer of a reform movement- Apostle
• One desirous of getting money- Avaricious
• One who is always dissatisfied - Malcontant
• One who does not care for literature or art- Philistine
• One who speaks for an idea- Advocate
• A man of odd habits- Eccentric
• One whose wife has been unfaithful to him- Cuckold
• One who pretends illness to escape duty- Malingerer
• One who tries to stir up people- Demagogue
• One who claiming to be superior in culture and intellect to others- Highbow
• One who pays too much attention to the cloths and appearances- Dandy
• A person who forsakes religion- Renegade/ Apostate
• Person holding a scholarship at a university - Bursar
• Person concerned with practical results and values- Pragmatist
• Person without manners or polish- Rustic 
• One who is made to bear the blame due to others- Scapegoat
• One who is honourably discharged from service- Emeritus