| core(noun, adjective, organization, support, action) |
| heart(noun, support, action, part, quality) |
| essence(noun, organization, support, action, area) |
| pith(noun, organization, area, part, quality) |
| enigma(noun, trouble, challenge, question, secret) |
| gist(noun, organization, area, part, strength) |
| nub(noun, part, quality, body, cause) |
| kernel(noun, part, quality, character, strength) |
| meat(noun, part, quality, character, strength) |
| substance(noun, organization, area, part, quality) |
| point(noun, support, quality, pass, character) |
| nucleus(noun, support, action, quality, body) |
| marrow(noun, quality, cause, start, character) |
| crisis(noun, trouble, pass, point, difficulty) |
| basis(noun, organization, action, area, quality) |
| problem(noun, trouble, difficulty, burden, challenge) |
| puzzle(noun, trouble, change, difficulty, challenge) |
| thrust(noun, part, body, strength, idea) |
| gravamen(noun, organization, area, strength, material) |
| mystery(noun, trouble, difficulty, challenge, question) |