under the skin

under (one's)/the skin

1. Inherently; essentially. In this usage, "the" is used between "under" and "skin." She's really a sweet girl under the skin—her sassy attitude just gets in the way of that sometimes.
2. Said of something that is a source of irritation. In this usage, a personal pronoun is used between "under" and "skin." I just can't stand Dean's voice, so everything he says gets under my skin.
3. Said of someone or something that one is obsessing about. In this usage, a personal pronoun is used between "under" and "skin." I can't get that beautiful girl I met earlier off my mind. She's just under my skin now.
See also: skin
Farlex Dictionary of Idioms.

under the skin

in reality, as opposed to superficial appearances.
See also: skin
Farlex Partner Idioms Dictionary

under the skin

Beneath the surface; fundamentally: enemies who are really brothers under the skin.
See also: skin
American Heritage® Dictionary of the English Language, Fifth Edition.
See also:
  • under (one's)/the skin
  • get under someone's skin, to
  • be (all) skin and bone(s)
  • be skin and bone
  • skin back
  • Skin me!
  • skin up
  • tight as a drum
  • (as) tight as a drum
  • Give me some skin!