HinKhoj Dictionary

Infants: <1

Children: 1-11 years or <7th grade

Teens: 12-17 or 7th-12th grade

Denarian: Someone age 10 to 19.

Vicenarian: Someone in his or her twenties.

Tricenarian: Someone in his or her thirties.

Quadragenarian: Someone in his or her forties.

Quinquagenarian: Someone in his or her fifties.

Sexagenarian: Someone in his or her sixties.

Septuagenarian: Someone in his or her seventies.

Octogenarian: Someone in his or her eighties.

Nonagenarian: Someone in his or her nineties.

Centenarian: Someone 100 or more.

Supercentenarian: Someone 110 years old or more (no upper limit).

Lasting for a very short time - Ephemeral
Spoken or done without preparation - Extempore
Release someone from a duty or obligation - Exonerate
Fond of company - Gregarious
Making marks that cannot be removed - Indelible
Incapable of making mistakes or being wrong - Infallible

Modality (noun): A Specific mode in which something is expressed or is experienced something exists (तौर-तरीका)
Antonym: Chaos, anarchy, differences

Cognizant (adjective): Having knowledge or awareness (जानकार)
Antonym: Ignorant, indifferent, senseless

Predicament (noun): A difficult, unpleasing or embarrassing situation (अप्रिय और कठिन स्थिति जिससे बाहर निकलना कठिन हो)
Antonym: Advantage, Benefit, Agreement, Blessing

Unanimously (adverb): Without opposition / with the approval of all the people involved (सर्वसम्‍मति से)
Antonym: Differently, divergently, oppositely

Precious (adjective): of great value (बहुमूल्‍य)
Antonyms: Cheap, common, impaired, deficient

EMBROIL (verb) उलझाना
Meaning: to involve in conflict or difficulties

RIVET (verb) ध्यान आकर्षित करना
Meaning: to attract and hold (something, such as a person’s attention) completely.

ELOQUENCE (noun) वाक्पटुता
Meaning: fluent or persuasive speaking or writing.

BADINAGE (noun) परिहास
Meaning: humorous or witty conversation.

Go through with - कोई काम अंत तक करते रहना 

Do you have the determination enough to go through with this job.

Go to law - कानून का सहारा लेना

In India, people go to law on very petty issues.

Go to town - कोई काम ध्यानपूर्वक करना

The interior decorator went to town on my flat and made it like a place.

Good humour - प्रसन्नचित होना

He has got a promotion today so he is in good humour.

Hammer and tongs - बड़े जोर-जोर से

The opposition went for the government's policies hammer and tongs.