Compounds of 繁

• 御用繁多
  (n,adj-na) being busy with many things
  extreme busyness due to pressure of business (often used humorously)
• 最繁正時
  (n) (comp) busy hour
  busy period
• 商売繁盛
  (n,vs) thriving (prosperous) business
  rush of business
• 繁殖牝馬
  (n) broodmare (horse breeding)
• 繁文縟礼
  (n) red-tapism
• 足繁く通う
  (exp) to visit frequently
  to haunt
• 最繁トラヒック時
  (n) (comp) peak traffic period