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1. The cardinal number equal to 1042.
2. Chiefly British The cardinal number equal to 1078.
[Latin tredecim, thirteen (trēs, three; see trei- in Indo-European roots + decem, ten; see deci-) + (m)illion.]
tre′de·cil′lionth adj.adv. & n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
1. (Mathematics) (in the short scale numerical system) the cardinal number of ten to the power of 42
2. (Mathematics) (in the long scale numerical system) the cardinal number of ten to the power of 78
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
tre•de•cil•lion(ˌtri dɪˈsɪl yən)
n., pl. -lions, (as after a numeral) -lion, n.
1. a cardinal number represented in the U.S. by 1 followed by 42 zeros, and in Great Britain by 1 followed by 78 zeros.adj.
2. amounting to one tredecillion in number.
tre`de•cil′lionth, adj., n.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.