Which term best describes someone who is skilled at using both hands?

The term that best describes someone who is skilled at using both hands is "ambidextrous." This word specifically refers to the ability to use both hands with equal skill, which is a rare trait in individuals. People who are ambidextrous can perform tasks such as writing, throwing, or playing musical instruments with either hand equally well.

The other terms listed have entirely different meanings. For instance, "acrimonious" describes something that is bitter or angry, often used in the context of relationships or debates. "Affidavit" refers to a written statement confirmed by oath or affirmation, used in legal contexts. "Adjudicator," on the other hand, refers to a person who makes a formal judgment or decision, often in a legal or competition setting. These definitions highlight why "ambidextrous" is the only choice that directly pertains to the ability to use both hands effectively.