at the top of her game

at Preposition

— Used to describe where something is, or when saying something's position I am at home. Let's meet at the pub! — The time at which something happened or will happen Breakfast is at 9 o'clock. At 5pm we went home. — Indicating something's state At half price! Water boils at high temperatures.

at Symbol

— The @ symbol, used to replace at support@microsoft.com is an email address. Apples @ £1.50 per kilogram.

the Determiner

— Used, instead of a, to reference something specific, already known to exist. Compare "I read a book." and "I read the book." — Used with a stress, to show that the word following is special. Are you the John Smith that I went to school with? — Used with an adjective that acts like a noun to mean all of the people concerned The poor are always with us. — Used with superlatives forms of adjectives and adverbs. You are the best.

top Noun

— The highest part of something; the upper part; the part people can put things on. The top of the table is flat. — A toy for children to play with. It is shaped like a funnel and it spins on its narrowest point. — A shirt

of Preposition

— Made using. It is a house of cards.

her Pronoun

— You use her instead of the name of a person, to talk about a woman or girl. (used in the object or complement position, never as a subject) This is Susan's book. Give it to her. — If you say something is her thing, you mean it belongs to a particular woman or girl. It is her book, not mine,

game Noun

— A game is something that people do to have fun. Shall we play a game? — Game are wild animals that are hunted for food. The forest is full of game.

game Verb

— To game means to play a game. Peter has been gaming for four hours without eating any lunch.