A smile, grin, or contortion of the face, indicative of contempt; an indirect expression or insinuation of contempt.
a facial expression of contempt or scorn; the upper lip curls
a contemptuous or scornful remark
express through a scornful smile; "she sneered her contempt"
smile contemptuously; "she sneered at her little sister's efforts to play the song on the piano"
A sneer is a scornful facial expression characterized by a slight raising of one corner of the upper lip.