An Encylopedia Britannica Company

inside

1 inside /ɪnˈsaɪd/ /ˈɪnˌsaɪd/ noun
plural insides
1 inside
/ɪnˈsaɪd/ /ˈɪnˌsaɪd/
noun
plural insides
Britannica Dictionary definition of INSIDE
[count] : an inner side, edge, or surface of something usually singular often + of
the inside : an inner part of something (such as a building or machine)
often plural
[count] informal : the inner parts (such as the heart and stomach) of a person's body usually plural

on the inside

: on the inner side, edge, or surface of something
baseball : on the side of home plate nearest the batter
used to describe how someone is feeling
: in a position within an organization or group
: in prison
2 inside /ɪnˈsaɪd/ /ˈɪnˌsaɪd/ adjective
2 inside
/ɪnˈsaɪd/ /ˈɪnˌsaɪd/
adjective
Britannica Dictionary definition of INSIDE
always used before a noun
: located on or near the inner side, edge, or surface of something
: coming from someone within a group or organization : relating to or having information that is known only to a special group of people
: done by someone within a group or organization
3 inside /ɪnˈsaɪd/ /ˈɪnˌsaɪd/ preposition
3 inside
/ɪnˈsaɪd/ /ˈɪnˌsaɪd/
preposition
Britannica Dictionary definition of INSIDE
: in or into the inner part of (something or someone)
: within the borders or limits of (something)
: before the end of (a period of time)
: belonging to (a group or organization)

inside of

chiefly US
: inside
4 inside /ɪnˈsaɪd/ /ˈɪnˌsaɪd/ adverb
4 inside
/ɪnˈsaɪd/ /ˈɪnˌsaɪd/
adverb
Britannica Dictionary definition of INSIDE
: in the inner part of something
: in or into the inner part of a building, room, etc.
informal : in prison

inside out

: so that the inner surface becomes the outer surface
informal : very well and thoroughly

turn (something) inside out

informal
: to cause (a place) to become disorganized while you are trying to find something
: to change (something) completely