| nave(noun, center, middle, target, centrality) |
| navel(noun, center, middle, target, centrality) |
| atom(noun, piece, bit, essence, nut) |
| centrum(noun, center, middle, target) |
| epicenter(noun, focus, middle, midpoint) |
| fraction |
| heart and soul(noun, expression, idiom) |
| hotbed(noun, center, middle, target, centrality) |
| interior(noun, center, middle, target) |
| iota(noun, piece, bit, morsel, seed) |
| keynote(noun, substance, idea, importance, short) |
| median(noun, middle) |
| nubbin(noun, essence, nut, seed, grain) |
| nuts and bolts(noun, expression, idiom, substance, idea) |
| omphalos(noun, center, middle, target) |
| ounce(noun, piece, bit, morsel, seed) |
| polestar(noun, place, emotion, quick, heart) |
| principle(noun, quality, character, spirit, idea) |
| sine qua non(expression, idiom, importance) |
| stuff(noun, quality, character, strength, spirit) |