bolus /bōˈləs/

1. A rounded mass
2. A large pill
3. A drug dose injected quickly into a blood vessel

• head to head
• head-to-head
• head up
• head-up display
• head voice
• head voices
• head waiter
• head waiters
• headwall
• headwater
• headwaters
• headway
• headways
• headwind
• headwinds
• head-woman
• head-women
• headword
• headwords
• headwork
• headworker
• headworkers
• headworks
• heady
• heal