spiceless (?.)

• dead
• dilute
• diluted
• fade
• flat
• flavorless
• gruelly
• inane
• indifferent
• insipid
• jejune
• mild
• milk-and-water
• pappy
• pulpy
• sapless
• savorless
• stale
• tasteless
• thin
• unflavored
• unsavory
• vapid
• washy
• watered
• watered-down
• watery
• weak
• wishy-washy