• 滞とどこおる — to stagnate; to be delayed; to get backed up
• 滞在たいざい — stay; temporary residence in a place
• 長期滞在ちょうきたいざい — long-term stay
• 停滞ていたい — standstill; stagnation (economy, traffic, etc.)
• 渋滞じゅうたい — traffic jam; heavy congestion
• 滞納たいのう — non-payment; falling behind on bills or taxes

On the left, the water element hints at flow. On the right, the part related to 帯 suggests something being held or tied around. Put together, 滞 paints the picture of water that should be moving but is held back — flow that slows down, piles up, and turns into a backlog.