thinners

noun
  1. 1

    A liquid substance used to thin the consistency of another liquid.

    โ€œTurpentine or mineral spirits can be used as a thinner for oil-based paints.โ€

  2. 2

    Something that thins.

    โ€œA solid mane thinner is indispensable in finishing the looks of your horse.โ€

Source: https://en.wiktionary.org/wiki/thinner, https://en.wiktionary.org/wiki/thinners