Root: Ag-, Act-

The Latin ag- or act- means "to do; drive". This root forms some of the most frequently used words in the English Language. You already know some common words based on it, such as act or action. Here are seven more core words based on the root ag- or act- that tou should know: agenda, agent, agile, active, actor, actual, enact.

Acute

acute stems from a Latin word meaning "to sharpen". Acute means "sharp" or "coming to a sharp point" and thus it has also come to mean "reaching a crisis; critical; keen; intense; violent". Note carefully these various meanings in the following sentences:
An acute angle is an angle of less than 90 degrees.
He is suffering from an acute appendicitis.
The food shortage in India is becoming acute.
The boy has a quick, acute mind.
His toothache was causing acute pain.
A word based on acute is acutely, meaning "intensely; extremely; keenly; highly".
He was acutely conscious of their disapproval.

Acumen

acumen comes directly from a Latin word meaning "sharpness of mind; intelligence".
Johny has shown great acumen in his schoolwork.

Acuity

acuity is made up of acu- meaning "sharp" and the Latin suffix -ity which means "the state, condition, or quality of being". Thus, acuity means "the state or condition of being sharp", but it is applied to sharpness or acuteness of the mind or senses.
The professor has great mental acuity.

Acrimony

acrimony comes from acr- meaning "sharp" and the Latin suffix -mony which means "quality of being". Specifically, acrimony means "sharpness of speech or temper".
Our quarrel was full of acrimony.
A word based on acrimony is acrimonious, meaning "full of bitterness; sharp; sarcastic".
Their discussion turned into an acrimonious debate.

Acrid

acrid comes from acr- meaning "sharp" and the Latin suffix -id meaning "having a particular quality". Thus, acrid means "having a sharp quality in taste or smell; bitter or burning to the senses".
The acrid smoke hurt our eyes.
A word based on acrid is acridity, meaning "the state or quality of being acrid; acridness".
The acridity of the smoke made our eyes water.

Root: Acu-, Acr-

The Latin root acu- or acr- means "sharp". You should sharpen your vocabulary with the five core words in which the root acu- or acr- appear: acrid, acrimony, acuity, acumen, acute.