1. Too small to be seen without an ultramicroscope

See also: ultramicroscope

• ablism
• abloom
• ABLS
• ablush
• ablution
• ablutionary
• ably
• ABM
• Abnaki
• abnegate
• abnegation
• abnegator
• Abney level
• abnormal
• abnormal psychology
• abnormalcy
• abnormality
• abnormally
• Abo
• ABO antibodies
• ABO blood group system
• ABO group
• ABO system
• aboard
• abocclusion