Importance is a property of entities that matter or make a difference. How to use importance in a sentence. Synonym Discussion of Importance. the quality of being important: 2. the quality of being important: 3. the quality of being…. Find 94 different ways to say IMPORTANCE, along with antonyms, related words, and example sentences at Thesaurus.com. Definition of importance noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. IMPORTANCE definition: the quality or state of being important; consequence; significance. See examples of importance used in a sentence. Importance is the state of being greatly significant. If you're invited to your cousin's wedding and your friend's circus-themed birthday party on the same day, you'll have to decide which event has more … The teacher lectured the students on the importance of mutual respect. a medical discovery of great/major importance [=a very important medical discovery] He exaggerated the importance of his ….