| fundamental(adjective, characteristic, foundation, basis) |
| mother(noun, source, foundation, basis, origin) |
| basal(adjective, characteristic, foundation, basis) |
| capital(adjective, characteristic, foundation, basis) |
| central(adjective, characteristic, foundation, basis) |
| chief(adjective, characteristic, foundation, basis) |
| critical(adjective, characteristic, foundation, basis) |
| elemental(adjective, characteristic, foundation, basis) |
| elementary(adjective, characteristic, foundation, basis) |
| essential(adjective, characteristic, foundation, basis) |
| indispensable(adjective, characteristic, foundation, basis) |
| inherent(adjective, characteristic, foundation, basis) |
| intrinsic(adjective, characteristic, foundation, basis) |
| key(adjective, characteristic, foundation, basis) |
| main(adjective, characteristic, foundation, basis) |
| necessary(adjective, characteristic, foundation, basis) |
| origin(noun, source, foundation, basis) |
| primary(adjective, characteristic, foundation, basis) |
| primitive(adjective, characteristic, foundation, basis) |
| principal(adjective, characteristic, foundation, basis) |