1 — used to indicate the place where someone or something is ▪ We’re staying at a hotel. ▪ The kitchen is at the back of the house. ▪ He was sitting at the table. ▪ They left for Cambridge early and arrived at [=in] Cambridge before noon. ▪ The party will be at Susan’s house. = The party will be at Susan’s. ▪ Ann works at [=in] a library. ▪ We met at a party. ▪ They live at opposite ends of town. ▪ They met at [=on] a street corner in a town. ▪ “Is your father at home?” [=is your father home?] “No, he’s working late at the office.” ▪ She met us at the door. ▪ He was standing at [=next to] the window. ▪ There were 200 people at the wedding. [=200 people attended the wedding] ▪ Their older son has graduated, but their younger son is still at school. [=is still attending school] ▪ Who was at the controls when the accident occurred?
The word at is used in speech in e-mail addresses.
▪ “Can I e-mail you?” “Sure. Our e-mail address is ‘comments at Merriam-Webster dot com.’” In writing, the symbol @ is used instead. ▪ comments@Merriam-Webster.com
2 — used to indicate the person or thing toward which an action, motion, or feeling is directed or aimed ▪ She pointed her gun at the target. ▪ He’s angry at his brother. ▪ His anger is directed at his brother. ▪ She shouted (words of) abuse at me. ▪ He looked directly at me. ▪ They laughed at him. ▪ She grabbed at my arm. [=she tried to grab my arm] ▪ He poked at his food.
3 — used to indicate something that is being tried or attempted ▪ I made an attempt at persuading him to go. ▪ I took a shot at doing it myself. [=I tried to do it myself]
4 : because of or in reaction to (something)
▪ They laughed at my joke. ▪ She’s furious at how slowly the investigation is proceeding. — used to indicate the cause of an action, feeling, etc. ▪ I was greatly surprised at [=by] the result. [=the result surprised me greatly] ▪ He enlisted in the army at his father’s urging. [=because his father urged him to] ▪ She visited the museum at my suggestion. ▪ They came here at our invitation. ▪ You can act at your own discretion.
5 — used to indicate an activity ▪ He’s very serious when he’s at work. [=when he’s working] ▪ children who are at play [=children who are playing] ▪ She’s good at (playing) chess. [=she plays chess well] ▪ I’m bad at cooking. [=I’m a bad cook, I do not cook well] ▪ She’s doing very well at her studies.
6 — used to indicate a situation or condition ▪ I’m not at liberty to discuss that. ▪ at rest ▪ two nations that are at war ▪ people who are at risk ▪ He is now at peace.
7 a — used to indicate position on a scale or in a series ▪ The temperature is at 90 degrees. ▪ He was driving at almost 80 miles an hour.
b — used to indicate a rate ▪ They sell at [=for] a dollar a dozen. [=each dozen costs one dollar]
8 — used to indicate an age or time ▪ He plans to retire at (age) 65. ▪ He called us at (about/exactly) 9 o’clock on July 24. ▪ at dawn/noon/sunset/night ▪ I still think of her at certain moments/times. ▪ He was president of the company at (the time of) his death.
9 — used to indicate the method by which something is done ▪ The property was sold at auction.