Vocaburary

Acerbic - sour, astringent in taste.
ex) Lemon juice is acerbic

Acidulous - slightly sour, moderate acid, caustic, sharp.
ex) His acidulous criticism of the book

Acme - the highest point, peak, summit, extremity.
ex) the empire was at the acme of its power

Acorn - the typically ovoid fruit, nut of an oak, enclosed at the base by a couple

Acquiesce - submit or comply silently or without protest; agree;
ex) to acquiesce halfheartedly in a business plan

Acquittal - the act of acquitting; discharge, the state of being acquitted; release.
ex) we can acquit them of all charges.

Acrimony - sharpness, harshness, bitterness of nature, speech, disposition.
ex) speaker attacked him with great acrimony.

Acrobatic -having the good balance, agility, and coordination of an acrobat.
ex) he performed an amazing acrobatic feat

Actuate - to incite or move to action, impel, motivate.
ex) actuated by selfish motives or to actuate a machine

Acuity - sharpness, keenness, acuteness.
ex) acuity of vision, acuity of mind