plain speech

plain speech (uncountable)

1. (Quakerism) A distinctive Quaker dialect of English, reformed on religious grounds and characterized by features such as use of the pronoun “thou” and numerical names for months and days of the week.
   • 1907, Warren Hugh Wilson, Quaker Hill: A Sociological Study, page 35:

     Another element of the “plain speech” is the use of such terms as “farewell” for “good day”—which is declared to be untruthful on bad days!

2. Used other than figuratively or idiomatically: see plain,‎ speech.

• plain dress

• Appendix:Quakerism