knapsack /napˈsak/

1. A bag made of strong material, with straps for carrying on the back, eg when hiking
2. A rucksack

• spermatorrhoea
• spermatorrhoeas
• spermatotheca
• spermatothecae
• spermatothecal
• spermatozoa
• spermatozoal
• spermatozoan
• spermatozoic
• spermatozoid
• spermatozoids
• spermatozoon
• sperm bank
• sperm banks
• sperm candle
• sperm candles
• sperm cell
• sperm cells
• sperm count
• sperm counts
• spermic
• spermicidal
• spermicide
• spermicides
• spermiduct