— undecillionth , adj. , n.
/un'di sil"yeuhn/ , n. , pl. undecillions , ( as after a numeral ) undecillion , adj.
n.
1. a cardinal number represented in the U.S. by 1 followed by 36 zeros, and in Great Britain by 1 followed by 66 zeros.
adj.
2. amounting to one undecillion in number.
[ 1930-35; undec ( im ) eleven ( un ( us ) one + -decim, comb. form of decem TEN) + -illion, as in million ]