"Great significance" refers to something that is extremely important or meaningful. It represents a high level of importance or relevance in a particular context or situation. Full definition
Participants will explore substantial texts and questions of great significance in an environment animated by a spirit of friendship and a common purpose. (firstthings.com)
This is what makes real estate a very prominent field, of great significance in today's times. (jeffadams.com)
This is a good example of how expansion of government regulation increases the number and influence of academic administrators — an institutional shift of great significance for higher education. (educationnext.org)