nosepiece

Short definition from Wiktionary

Noun

1. 1
   Anything (originally a piece of armour) that protects the nose.
2. 2
   An animal's noseband.
3. 3
   The bridge between spectacle lenses that rests on the nose.
4. 4
   The part of a microscope that holds the objectives.
5. 5
   The outer end or point of a pipe, bellows, etc.