know one's stuff

Also, know one's onions. Be experienced or knowledgeable in one's field or in the matter at hand. For example, Patrice knows her stuff when it comes to Mexican history, or We need a handyman who knows his onions. The allusion in the variant is unclear. [First half of 1900s]


Nearby words

  1. know if one is coming or going,
  2. know it all,
  3. know like a book,
  4. know one's own mind,
  5. know one's place,
  6. know one's way around,
  7. know only too well,
  8. know the ropes,
  9. know the score,
  10. know where one stands

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.