regrettable：令人遗憾的，可惜的，可悲的  

词根词缀：regret遗憾,懊悔 + -able形容词词尾

• measles
• measly
• measurable
• measure
• measured
• measureless
• measurement
• meat
• meat and potatoes
• meat and two veg
• meaty
• mebibit
• mebibyte
• Mecca
• mecca
• mechanic
• mechanical
• mechanician
• mechanics
• mechanism
• mechanist
• mechanistic
• mechanize
• medal
• medallion