1. With bitterness, in a resentful manner
   "she complained bitterly" 
2. Indicating something hard to accept
   "he was bitterly disappointed" 
3. Extremely and sharply
   "it was bitterly cold"
   - piercingly, bitingly, bitter

See also: bitter

• genus Microsporum
• genus Microstomus
• genus Microstrobos
• genus Microtus
• genus Micruroides
• genus Micrurus
• genus Mikania
• genus Millettia
• genus Miltonia
• genus Mimosa
• genus Mimus
• genus Minuartia
• genus Mirabilis
• genus Mirounga
• genus Mitchella
• genus Mitella
• genus Mnium
• genus Mobula
• genus Moehringia
• genus Mohria
• genus Mola
• genus Mollienesia
• genus Molluga
• genus Moloch
• genus Molothrus