| head(noun, superior, boss, leader, chief) |
| head honcho(noun, expression, head, boss, leader) |
| head person(noun, boss, leader, chief, major) |
| heavyweight(noun, superior, head, boss, leader) |
| higher-up(noun, superior, boss, leader, management) |
| initial cause(expression, reason, importance, significance) |
| issue main reason(expression, reason, importance, significance) |
| key condition(expression, reason, importance, significance) |
| key element(expression, reason, importance, significance) |
| key enabler(expression, reason, importance, significance) |
| key factor(expression, moment, influence, importance) |
| key idea(expression, reason, importance, significance) |
| key pillar(expression, reason, importance, significance) |
| key reason(expression, reason, importance, significance) |
| leader(noun, head, boss, chief, major) |
| main cause(expression, reason, importance, significance) |
| main condition(expression, reason, importance, significance) |
| main criterion(expression, reason, importance, significance) |
| main culprit(expression, reason, importance, significance) |
| main reason(expression, reason, importance, significance) |