• 排出はいしゅつ — discharge; emission
• 排気はいき — exhaust (gas); ventilation
• 排水はいすい — drainage
• 排便はいべん — bowel movement; evacuation
• 排除はいじょ — removal; exclusion
• 排卵はいらん — ovulation
• 排おしのける — to push aside; to elbow out

With the hand radical 扌, 排 is the hand actively clearing space — pushing things out, lining them up, or expelling what doesn’t belong.