put on side

put on side

dated To think or behave as though one is superior to others or better than one really is; to have or assume a pretentious or self-aggrandizing attitude. Primarily heard in UK. I think John is really a decent fellow at heart, but I really wish he wouldn't put on such side about his writing abilities. Stop putting on side, Mary. You're not some world-class actor—you're just an amateur like the rest of us!
See also: on, put, side
Farlex Dictionary of Idioms.

side

n. a side of a record (recording). (Refers to older vinyl recording.) Let’s cruise over to Sam’s pad and hear some sides.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • assume
  • assume airs
  • assumed
  • give (oneself) airs
  • drive (one) out of office
  • force (one) out of office
  • force out of office
  • give head
  • give somebody their head
  • give someone their head