inside out /ˌɪnsaɪdˈaʊt/adverb 4inside-out adjective 3 adverb4 •With the inside surface turned to be on the outside.I now realise that I have my shirt on inside out. •Thoroughly; extremely well.I know IBM Assembler Language inside out. •Completely; through and through; to the core.We're hometown hockey fans inside out. •Describes the hitting of a ball that pitched outside of leg stump to the off side of the field.He hit the ball inside out in an ugly manner, but scored a four. inside-out adjective3 •With the inner and outer surfaces reversed.These curious gloves... have two thumbs, so that by an inside-out process they can get another pair of gloves when the palm becomes worn out. — 1893 •Describing cross-court shots made by the unexpected hand, as of a backhand return of a ball struck to the player's forehand....cracking an ‘inside-out’ backhand past Rahim on the set point... — 1977 •(no longer used, rare) Synonym of sidelong....with a nudge of the elbow, and an inside-out squint of his eyes... — 1850