fickle
The definition for fickle is "Lacking constancy, changeable." Used in a sentence: The fickle Senji had a new best friend every month.
futile
The definition for futile is "Without purpose, completely ineffective." Used in a sentence: Arguing with Andrew is futile because he never changes his mind.
genial
The definition for genial is "Sympathetic, friendly." Used in a sentence: The genial host warmly greeted his many guests.
liability
The definition for liability is "A person or thing whose presence or behavior is likely to cause embarrassment or put one at a disadvantage." Used in a sentence: Kevin's growing fatigue was a liability as he attempted to climb the steep hill.
proximity
The definition for proximity is "Closeness." Used in a sentence: The proximity of Tia's house to school meant that she could walk there in five minutes.