Ambidextrousnesses refers to the ability to use both hands with equal proficiency. The antonyms of the word "ambidextrousnesses" refer to the opposite of this ability. The antonyms for ambidextrousnesses include words such as clumsy, awkward, uncoordinated, and inept. These words describe a lack of dexterity, and an inability to perform tasks with ease and grace. Someone who is clumsy may find it difficult to handle small objects, perform intricate tasks, or manipulate tools with precision. Those who lack ambidextrousnesses may need to work harder to develop their coordination and dexterity, but it can be developed with practice and patience.