archaic
The definition for archaic is "Characteristic of an earlier time." Used in a sentence: In the world of high fashion, two–year–old shoes are considered positively archaic.
flaw
The definition for flaw is "An imperfection." Used in a sentence: The otherwise perfect diamond had a tiny flaw that reduced its value.
implement
The definition for implement is "To carry out or accomplish." Used in a sentence: All Randolph needed to implement his plan was a moonless night and a long rope.
serenity
The definition for serenity is "Calmness." Used in a sentence: The serenity of the glassy sea soothed the sailors after the big storm.
sociable
The definition for sociable is "Inclined to seek companionship." Used in a sentence: The sociable Glenda was delighted to receive the party invitation.