monacid /mon-asˈid/ or monoacid /mo-nō-asˈid/

1. Having one replaceable hydrogen atom
2. Capable of replacing one hydrogen atom of an acid

• helplessly
• helplessness
• helplessnesses
• helpline
• helplines
• helpmate
• helpmates
• helpmeet
• helpmeets
• help off with
• help oneself
• help oneself to
• help on with
• help out
• helps
• helter-skelter
• helter-skelteriness
• helter-skelters
• helve
• helved
• helve-hammer
• helve-hammers
• helves
• Helvetian
• Helvetic