definition for sniff
/ËsnÉªf/. noun. plural sniffs. Learner's definition of SNIFF. 1. [count] : an act or the sound of drawing air into the nose especially in order to smell something or because you are sick or have been crying. He took a big sniff [= whiff ] of the soup. She said that she felt fine, but her sniffs and coughs told a different story.