- Rhymes: -ɪljən
- (rare, US, modern British & Australian, short scale) 1042.
- 1896, Frank H. Hall, The Werner Arithmetic, Oral and Written, Book Two, Parts I and II:
- The names of the periods above trillion are as follows [...] 15th, tredecillion [...]
- 1946, United States Department of Commerce, The United States Department of Commerce: How it serves you on land and sea and in the air:
- 3 quindecillion, 657 quattuordecillion, 262 tredecillion; which is to say the figures 3,657,262 followed by 42 ciphers. Operators of the key punch machines transfer a code symbol from the Census [...].
- 1994, National Council of Teachers of Mathematics, The Arithmetic Teacher, National Council of Teachers of Mathematics (1994):
- The answer is read as: 13 sexdecillion, 253 quindecillion, 796 quattuordecillion, 742 tredecillion, [...].
- (rare, dated, Britain, Australia, long scale) 1078.
- Words of Mathematics: An Etymological Dictionary of Mathematical Terms Used in English (1994).