| principal(noun, person, superior, head, boss) |
| principal cause(expression, reason, importance, significance) |
| reason fundamental(expression, reason, importance, significance) |
| ringleader(noun, leader, general, major, superstar) |
| root cause(expression, reason, importance, significance) |
| root motive(expression, reason, importance, significance) |
| root source(expression, reason, importance, significance) |
| ruler(noun, superior, head, boss, general) |
| shaping factor(expression, reason, importance, significance) |
| supervisor(noun, superior, head, boss, leader) |
| suzerain(noun, leader, general, major, superstar) |
| top cat(noun, expression, leader, general, major) |
| top dog(noun, expression, head, leader, major) |
| top priority(expression, reason, importance, significance) |
| tycoon |
| ultimate cause(expression, reason, importance, significance) |
| underlying cause(expression, reason, importance, significance) |
| upstream cause(expression, reason, importance, significance) |
| administration(noun, government, leader, management, director) |
| admiral(leader, major, commandant) |