itself

Etymology

From Middle English hit-self, equivalent to it + -self.

pron

1. (reflexive) it; A thing as the object of a verb or preposition that also appears as the subject
   The door closed by itself
2. (emphatic) it; used to intensify the subject, especially to emphasize that it is the only participant in the predicate
   The door itself is quite heavy.
3. (emphatic, archaic) it; used to refer back to an earlier subject
   The oil by degrees gets covered with a curdy mass, which after some time settles to the bottom, while itself becomes limpid and colorless. 1842, Andrew Ure, A Dictionary of Arts, Manufactures and Mines