component

noun

1. 1

   an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system

   spare components for cars

   a component or constituent element of a system

2. 2

   an abstract part of something

   jealousy was a component of his character

   two constituents of a musical composition are melody and harmony

3. 3

   something determined in relation to something that includes it

   he wanted to feel a part of something bigger than himself

   I read a portion of the manuscript