ADD - To join or unite, as one thing to another, or as several particulars, so as to increase the number, augment the quantity, or enlarge the magnitude, or so as to form into one aggregate. Hence: To sum up; to put together mentally.
AID - Help; assistance; succor, relief.
AND - As a coordinating conjunction; expressing two elements to be taken together or in addition to each other.
DAD - A father, a male parent.
DID - A Roman numeral representing nine hundred and ninety-nine (999).
CAD - A person who stands at the door of an omnibus to open and shut it, and to receive fares; an idle hanger-on about innyards.
DIN - A loud noise; a cacophony or loud commotion.
ACID - Sour, sharp, or biting to the taste; tart; having the taste of vinegar.
CANDID - Impartial and free from prejudice.