Having zero zip
Else clues• Bland
• Brainless
• Dull
• Dull as dishwater
• Flat
• Flavorless
• Hardly stimulating
• Insipid
• Lacking life
• Lacking liveliness
• Lacking sharpness
• Lacking spirit
• Lacking tang
• Lacking zest
• Lifeless
• Not very interesting
• Prosaic
• Spiritless
• Unanimated
• Uninspired
• Uninspiring
• Uninteresting
• Very uninteresting
• Watered down
• Wishy-washy