The Rice University Neologisms Database

The end of a loaf of crusted bread. The ‘nose’ if a loaf of bread is similar to the ‘heel’ or ‘butt’ of the loaf but implies a shape that is tapered or domed, meaning the term is not applied to cross-sectionally square sandwich bread. The term may have been generalized from a bread ‘nose’ referring specifically to the end pieces of baguettes because of their similarity to the shape of the human nose. The term may have instead been derived more generally from the idea of a protuberance on the front of something. Like ‘heel’ and ‘butt,’ which have metaphorically connected meanings as both body parts and locations on a long object, the term ‘nose’ may have been either coined directly from its resemblance to the body part or from the metaphorical meaning of ‘nose’ as the protruding front end of an object.