a combining form used in the names of units of measure equal to one quadrillion (1015) of a given base unit: petabyte.

Nearby words

  1. pet scanning,
  2. pet sitting,
  3. pet.,
  4. pet.e.,
  5. peta,
  6. petabyte,
  7. petach tikva,
  8. petah tiqwa,
  9. petahertz,
  10. petal

Origin of peta-

origin uncertain Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for peta

British Dictionary definitions for peta


abbreviation for

People for the Ethical Treatment of Animals



denoting 10 15petametres Symbol: P

Word Origin for peta-

C20: so named because it is the SI prefix after tera-; on the model of penta-, the prefix after tetra-

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for peta


acronym for People for the Ethical Treatment of Animals; the group’s website says it was founded in 1980.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for peta



One quadrillion (1015):petagram.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for peta


A prefix that means:
One quadrillion (1015), as in petahertz, one quadrillion hertz.
250 (that is, 1,125,899,906,842,624), which is the power of two closest to a quadrillion, as in petabyte.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.