The phrase "being up ears in" means being fully engaged or interested in something. Its antonyms could be: disinterested, uninterested, indifferent, apathetic, bored, unconcerned, inattentive, distracted, and aloof. These words describe the opposite of being fully engaged or interested in something. Disinterested and uninterested are similar, but disinterested more often means fair and impartial, while uninterested means not interested. Indifferent, apathetic, and unconcerned suggest a lack of interest or enthusiasm. Bored implies feeling no interest due to dullness or monotony. Inattentive and distracted describe being easily distracted or losing focus. Aloof means detached, unfriendly, or uninvolved.