ad
- 1Short for advertisement: a public message promoting something to buy, a job, an event, a person or a cause.
I saw an ad for cheap flights on my phone.
There are way too many ads on this website.
UsageYou post an ad, or see an ad for something.
- 2Initialism of Anno Domini. Used with dates in the time counted from the birth of Jesus.
This old coin was made around AD 300.
The town was founded in the fifth century AD.
UsageWrite AD 300, but the fourth century AD.
- 3Short for athletic director: the person in charge of the sports programs at a school or college.
The AD hired a new basketball coach this spring.
Our school's AD makes the game schedule for every team.
UsageSay each letter. More than one is ADs.
- 4Sayay-DEE/ˌeɪˈdi/UK/ˌeɪˈdiː/Short for Alzheimer's disease: a brain disease that slowly takes away memory and thinking.
Doctors use a new blood test to look for early signs of AD.
The clinic runs a support group for families dealing with AD.
UsageSay people have AD.
Less common meanings
- 5Sayay-DEE/ˌeɪˈdi/UK/ˌeɪˈdiː/Short for assistant director: a person who helps a film or TV director run things on set.
The AD told the actors to take their places.
She worked as an AD on two TV shows.
Note
- 6In tennis, short for advantage. Also the left side of the court, where the point after deuce is played.
It's ad in, so one more point wins the game.
She likes to return serve from the ad side.
UsagePlayers say ad in or ad out after deuce.
Similaradvantage
Note
- 7Sayay-DEE/ˌeɪˈdi/UK/ˌeɪˈdiː/Short for audio description: spoken words describing screen or stage action for people who are blind or have poor sight.
You can switch on AD in the TV menu.
My grandma watches every movie with AD turned on.
UsageYou can switch on AD in the TV menu.
Note
- 8A short way to say advertising, the business of getting people to buy things, mostly used before another noun.
My aunt works at an ad agency in Chicago.
He left the ad business to become a teacher.
UsagePut it before another noun, like ad agency. Alone, say advertising: she works in advertising.
Similaradvertising
Note
- 9Means to or toward. It comes from Latin.
- 10Short for advertiser: a person or group that uses ads to promote something.
- 11Short for antidepressant: a medicine used to treat depression and other conditions, such as anxiety.
- 12Short for airworthiness directive: an official order to check or fix certain aircraft so they are safe to fly.
- 13Short for adenovirus: a kind of virus that can cause colds and is also used to make some vaccines.
- 14Short for air defence or air defense: weapons and troops that protect against attacks from the air.
- 15Short for Abu Dhabi: the capital of the United Arab Emirates, or the emirate that includes this city.
- 16Initialism of auxiliary destroyer. In the US Navy, the letters for a ship that supplies and repairs destroyers.
- 17Short for antidumping: describing steps against imports sold below cost or their price in the country they come from.
- 18Initialism of after dark. Online, it means an account a creator keeps for followers aged 18 and over.
- 19In debating, a short way to say advantage.
Showing meanings only.
Practice
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Origins
A short form of advertisement and related words.
Checked 31 Oct 2026 · 1 fact
- Ad is a shortened form of advertisement and related words, including advertise, advertising, and advertiser. en.wiktionary.org
A short form of the word advantage.
Checked 31 Oct 2026 · 1 fact
- Ad is a short form of advantage. en.wiktionary.org