sidewall

/S AY1 D W AO0 L/
noun
  1. 1

    The side of a tire.

    โ€œIf the puncture had been in the tread I could have had the tire patched, but it was in the sidewall and they can't fix that: they have to replace the whole tire.โ€

  2. 2

    The wall forming the side of a structure; a side wall.

Source: https://en.wiktionary.org/wiki/sidewall