IDIOMS

words of one syllable

(idiomatic, usually preceded by in) Simple, clear, straightforward language; blunt language.

Example: 1894, John Kendrick Bangs, "A Midnight Visitor" in The Water Ghost and Others:
  I am at present engaged in preparing a vest-pocket edition of the philosophical works of Schopenhauer in words of one syllable.
1914, Samuel Hopkins Adams, The Clarion, ch. 24:
  So I explained in words of one syllable that I went there to pick edelweiss from the fire escapes.
1915, John Galsworthy, The Freelands, ch. 22:
  Felix propounded the story of the arrest, so far as might be, in words of one syllable.
1972 Dec. 27, Alden Whitman, "Obituary: Harry S. Truman, Decisive President," New York Times (retrieved 21 Sep 2012):
  The President used "words of one syllable" to convey his insistence that Poland be "free and independent".
2003 Nov. 19, Richard Corliss, "That Old Feeling: The Show at the Casino," Time:
  Or, in words of one syllable, it's Cirque's sex show.