retroactive

1 of 2

adjective

ret·​ro·​ac·​tive ˌre-trō-ˈak-tiv 

: extending in scope or effect to a prior time or to conditions that existed or originated in the past

especially : made effective as of a date prior to enactment, promulgation, or imposition

retroactive tax

retroactively adverb

retroactivity

ˌre-trō-ˌak-ˈti-və-tē 

noun

retroactivity

2 of 2

noun

ret·​ro·​activity "+ 

1

: the quality or state of being retroactive

2

: the capacity of a bacterial agent in biological warfare to react upon the user

Did you know?

We normally think of time as constantly moving forward. Since retroactive seems to defy time's forward movement, retroactive taxes, laws, and regulations are often seen as particularly obnoxious and unfair. But nobody ever objects to receiving a retroactive raise at work. When we judge historical people and events in terms of present-day morality and attitudes, our retroactive judgments may indicate that we're too impressed with ourselves and ignorant of history.

Examples of retroactive in a Sentence

Adjective

They all received a retroactive pay raise.

The new tax will be retroactive to January 1.

Recent Examples on the Web

Adjective

The Supreme Court further held that such a tax was unconstitutional even if only retroactive to a period where the taxpayer would have realized the tax was possible or even likely. — Jared Walczak, San Diego Union-Tribune, 31 July 2026

This isn’t the first time the company has treated subscribers to a retroactive increase, having done so in 2024. — Rob Pegoraro, PC Magazine, 31 July 2026

These options vary significantly, including deferred interest, where no interest is charged if the balance is paid in full by a deadline, but retroactive interest applies if not. — Louis Denicola, Forbes.com, 28 July 2026

Rather than retroactive investigation, tools do exist to detect abuse during transmission. — Charlie Campbell, Time, 20 July 2026

Word History

Etymology

Adjective

French rétroactif, from Latin retroactus, past participle of retroagere to drive back, reverse, from retro- + agere to drive — more at agent

First Known Use

Adjective

1611, in the meaning defined above

Rhymes for retroactive

• attractive
• contractive
• extractive
• inactive
• proactive
• reactive
• refractive
• subtractive
• active
• tractive
• bioactive
• hyperactive

Kids Definition

retroactive

adjective

ret·​ro·​ac·​tive ˌre-trō-ˈak-tiv 

: intended to apply or take effect at a date in the past

a retroactive pay raise

retroactively adverb

Medical Definition

retroactive

adjective

ret·​ro·​ac·​tive ˌre-trō-ˈak-tiv 

: having relation or reference to or efficacy in a prior time

specifically : relating to, caused by, or being obliteration of the results of learning by immediately subsequent activity

retroactive inhibition

Legal Definition

retroactive

adjective

ret·​ro·​ac·​tive ˌre-trō-ˈak-tiv 

: extending in scope or effect to a prior time or to conditions that existed or originated in the past

especially : made effective as of a date prior to enactment, promulgation, or imposition

a retroactive tax

see also ex post facto law

retroactively adverb

retroactivity

-ak-ˈti-və-tē 

noun