A trillionth of something is a very small amount. To say that something is a trillionth of something is to say that it is very, very small.

  • The car is a trillionth of a mile away.

  • The number of stars in the sky is a trillionth of a million.

Definition of trillionth


one part in a trillion equal parts




the ordinal number of one trillion in counting order

Nearby Words

trillionth Pronunciation in a video (3)

Example Sentences for trillionth

  • 1

    You are looking for a particle that will exist for one billion trillionth of a second before metamorphosing not just once but twice.

  • 2

    A picosecond is one trillionth of a second.

  • 3

    The picowatt is equal to one trillionth of a watt.

  • 4

    They're only the 4 trillionth company to do it.

  • 5

    The prefix pico , literally defined as one trillionth, is a minute fraction.

  • 6

    Maybe one part per billion Carbon, and some trillionth of C 14.