Retroactive
/ˌrɛtrəʊˈæktɪv/noun
Applying to or taking effect from a date, action, or event in the past.
Did you know?The hidden power here is Latin: the prefix retro- means “backward,” and the word’s force comes from the same ancient root behind movement, return, and reversal.
Etymological Timeline
Proto-Indo-European
PIE
*wert-
“to turn, roll, or rotate”
Latin
Latin
vertere
“to turn”
Latin
Latin
retro
“backward, behind”
17th Century
English
retroactive
“acting backward in time or effect”
Modern English
English
retroactive
“taking effect as if from an earlier date”
Explore more surprising origins