Definition of "trillion" []

• The cardinal number equal to 1012. (noun)
• Chiefly British The cardinal number equal to 1018. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "If the risk of sea level rise, species extinctions, disrupted agriculture, new infrastructure investments required to adapt to catastrophic climate change, etc can be valued at $20 trillion in "net present value" (NPV ... value today, in today's dollars), then an investment of $trillion or $4 trillion to obviate that risk is a well-spent insurance policy."
• "The term trillion makes all of this somewhat hard to grasp."
• "I would have not known this, but I quickly learned it by looking up the term trillion in Wolfram|Alpha."