The dictionary says "To state or express in a concise word."
I say to say something by using as little brain work as possible.
Long version:
"And like a flower in the moonlight, she glided gracefully down the aisle."
Summarized version:
"Why can't you just said she walked down the aisle?"
Summarizing is to take a sentence and shorten it, but remember to shorten only to the important details so the reader can still understand it. Also the word that your teacher is probably teaching you.
Teacher: You summarize by shortening the sentence and putting the important details.
Kid: Oh speedrun
Teacher: 💀💀💀
Kid: *ASCENDS TO GOD*
Teacher: 💀💀💀💀💀💀💀💀💀
When someone makes a comment and someone else repeats it soon after, claiming it as their own. Often, but not always, trying to one up the original idea.
Tamara: My husband was lit last night, I apologize for him at the wedding, he was plowed and loud.
Brie: I had a blast with Adam - classic Adam. He was ordering everyone bushwhackers with floaters, though ordering his bushwhackers with a submarine shot as well as a floater!