Definitions: (adjective) When something is crucial, it is very important. It will make a big difference. You cannot succeed without it.
Examples: (adjective) It was a crucial time in the battle when the king dropped his sword. (adjective) To write a great book, it’s crucial to have the person in the book change and develop.
Synonyms: adjectives: central, important, necessary.
Academic Word List Sublist and Group: 8 E