Undo
/ʌnˈduː/noun
To reverse or cancel the effect of something.
Did you know?The word is an Old English prefix-plus-verb formation, and its power is so basic that it became one of the clearest everyday examples of English expressing reversal by literally saying “not-do.”
Etymological Timeline
Old English
OE
undōn
“to unfasten, open, or reverse an action”
Proto-Germanic
PGmc
*andōną / *undojaną
“to open, unfasten, or take apart”
Proto-Indo-European
PIE
*h₁en-
“in, on, into; a directional particle that developed into Germanic prefixal forms”
Middle English
ME
undo(n)
“to unfasten, untie, or reverse”
Modern English
English
undo
“to reverse or cancel the effect of something”