1º_ Relative to the ear, to the ear. From the Latin auriculare ("of the little ear"), which has an origin in the Greek 959; 965; 962; ( ous "ear, auditory perception") . See in-ear. 2º_ For the above is any artifact that rests on the ear to receive sound. In this case it is very common to use in the plural, when it is usually placed in both . See hearing aid . 3º_ Relative to the atrium of the heart.