preposition
inside (a certain area or space)
inside (a group, company, society, etc.)
before the end of (a particular period of time)
less than (a particular distance) from something or someone
not beyond the limits of (something)
used to say how close someone is or was to doing or achieving something
in the thoughts or character of (someone)
adverb
formal
inside something
in someone's inner thoughts, feelings, etc.
US