someday

[ suhm-dey ]
/ ˈsʌmˌdeɪ /

adverb

at an indefinite future time.

Origin of someday

before 900; Middle English sum day, Old English sum dæg; see some, day

usage note for someday

The adverb someday is written solid: Perhaps someday we will know the truth. The two-word form some day means “a specific but unnamed day”: We will reschedule the meeting for some day when everyone can attend.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for someday

British Dictionary definitions for someday

someday
/ (ˈsʌmˌdeɪ) /

adverb

at some unspecified time in the (distant) future
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