inside out

Short definition from Wiktionary

Adverb

1. 1
   With the inside surface turned to be on the outside.
2. 2
   Thoroughly; extremely well.
3. 3
   Completely; through and through; to the core.
4. 4
   Describes the hitting of a ball that pitched outside of leg stump to the off side of the field.
5. 5
   Alternative form of inside out.

Adjective

1. 1
   Alternative form of inside-out.
2. 2
   Synonym of sidelong.
3. 3
   With the inner and outer surfaces reversed.
4. 4
   Describing cross-court shots made by the unexpected hand, as of a backhand return of a ball struck to the player's forehand.