| mainstream(noun, place, moderate, ordinary, usual) |
| axis(noun, center, middle, target) |
| centrality(noun, center, middle, target) |
| centriole(noun, center, middle, target) |
| centrum(noun, center, middle, target) |
| cookie-cutter(adjective, characteristic, quality, regularity, commonplaceness) |
| core(noun, center, middle, target) |
| cynosure(noun, center, middle, target) |
| equidistance(noun, center, middle, target) |
| essence(noun, center, middle, target) |
| focal point(noun, center, middle, target) |
| gist(noun, center, middle, target) |
| heart(noun, center, middle, target) |
| hotbed(noun, center, middle, target) |
| hub(noun, center, middle, target) |
| inside(noun, center, middle, target) |
| interior(noun, center, middle, target) |
| intermediacy(noun, center, middle, target) |
| kernel(noun, center, middle, target) |
| marrow(noun, center, middle, target) |