itself

itself /ɪtˈsɛlf/ pronoun
itself
/ɪtˈsɛlf/
pronoun
Britannica Dictionary definition of ITSELF
1 
: that same one:
a  — used as the object of a verb or preposition to refer to something that has already been mentioned
b  — used for emphasis to refer to something that has already been mentioned
2 
— used after a noun to say that someone or something has a lot of a particular quality

by itself

1 
: on its own : without being directly controlled by a person
2 
: with nothing nearby : alone

in itself

: in its own nature : when considered as something separate from other things
: without anything else added — see also an end in itself at 1end