aleatory

[ ey-lee-uh-tawr-ee, -tohr-ee, al-ee- ]
/ ˈeɪ li əˌtɔr i, -ˌtoʊr i, ˈæl i- /

adjective

Law. depending on a contingent event: an aleatory contract.
of or relating to accidental causes; of luck or chance; unpredictable: an aleatory element.
Music. employing the element of chance in the choice of tones, rests, durations, rhythms, dynamics, etc.
Also a·le·a·tor·ic [ey-lee-uh-tawr-ik, -tor-, al-ee-] /ˌeɪ li əˈtɔr ɪk, -ˈtɒr-, ˌæl i-/.

Origin of aleatory

1685–95; < Latin āleātōrius, equivalent to āleātōr- (stem of āleātor gambler (āle(a) game of chance + -ātor -ator) + -ius adj. suffix; see -tory1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for aleatoric

aleatory

aleatoric (ˌeɪlɪəˈtɒrɪk)

/ (ˈeɪlɪətərɪ, -trɪ) /

adjective

dependent on chance
(esp of a musical composition) involving elements chosen at random by the performer

Word Origin for aleatory

C17: from Latin āleātōrius, from āleātor gambler, from ālea game of chance, dice, of uncertain origin
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012