English edit

Etymology edit

From sit in or sit-in.

Noun edit

sitter-in (plural sitters-in)

  1. One who attends a class, meeting, etc.
  2. One who takes part in a sit-in protest.
    • 1960, LIFE, volume 49, number 12, page 42:
      Except for a few adult leaders like the Rev. Robert Williams, shown below conducting a strategy seminar, the sitters-in are youngsters like Virginius Bray Thornton who, at right, is leading a march through Petersburg.