WordNet sense 1 (the capacity to understand a broad range of topics):

breadth, comprehensiveness

WordNet sense 2 (large or extensive in breadth or importance or comprehensiveness):

extensiveness

WordNet sense 3 (the property of having a relatively great size):

bigness

WordNet sense 4 (the quality of being pretentious (behaving or speaking in such a manner as to create a false appearance of great importance or worth)):

pretension, pretentiousness