a-, an-



It affects the meanings of hundreds of words.


agnathia (s) (noun), agnathias (pl)
A complete or partial absence of one or both jaws: After the accident, Sammy had partial left agnathia and so he had to learn to speak again.
agnosia (s) (noun), agnosias (pl)
1. The inability to recognize certain sensory stimuli: Because of an extensive neural damage as the result of the car accident, Paul's friend experienced aural agnosia.
2. Loss of the ability to recognize people or objects and their meanings: A tragic consequence of the industrial accident was the onset of agnosia making it impossible for some of the workers to continue working because they couldn't remember how to perform their jobs anymore.
3. In medicine, losses of comprehensions at the levels of central nervous systems of any of the senses: The sensory spheres of the agnosias may be intact, but Linda is unable to assimilate the meanings of whatever the senses indicate.
agnosis (s) (noun), agnoses (pl)
The total or partial loss of the abilities to recognize familiar objects, often resulting from brain damage: Disabilities in recognizing things may affect any of the senses and is classified accordingly as auditory, visual, olfactory, gustatory, or tactile agnosis.
agnostic (s) (noun), agnostics (pl)
1. Not known or that which is unknown; an assertion of the uncertainty of all claims to knowledge: The word agnostic was invented, or coined, by T.H. Huxley, the eminent British biologist, in his Science and Christian Tradition, published in 1870, page 21; because he felt that the existence of God was a proposition that could not be proven scientifically. So an agnostic says, in effect, "There may be a God, but as for me, I do not know."
2. A person who believes that the existence of God is unknown, but does not deny the possibility that God exists: Sherman, who was an agnostic, was not convinced that there is a God; however, he also was open to considering any evidence that would prove that God is a reality.
3. Someone who thinks it is impossible to know whether there is a God, future life, or anything beyond the material phenomena we are experiencing and who is unwilling to accept supernatural revelation: One dictionary defines an agnostic as being someone who is not, as is often held, someone who doesn’t know whether there is a God, but a person who believes it is impossible to know or to prove anything about the existence of God.

An agnostic is someone who says he knows nothing about God, and when you agree with him, he becomes angry.

—Evan Esar

An agnostic is someone who has no invisible means of support.

—John Buchan
agonic (adjective), more agonic, most agonic
Characteristic of not forming an angle; having no angle: The line indicating the perimeter of a circle is an agonic line.
agrammaphasia (s) (noun), agrammaphasias (pl)
Ungrammatical speech: Agrammaphasia is a form of aphasia, in which Susan, with this disability, forms words into a sentence without regard for any of the grammatical rules.

Agrammaphasias are usually caused by a cerebral disease that is characterized by an inability to construct a grammatical or intelligible sentence while still having the ability to speak single words.

agrapha (s) (noun), agraphas (pl)
agraphesthesia (s) (noun), agraphesthesias (pl)



agraphia (s) (noun), agraphias (pl)
agraphic (adjective), more agraphic, most agraphic
agraphognosia (s) (noun), agraphognosias (pl)


ahydrotaxis (s) (noun), ahydrotaxes (pl)
Organisms or creatures that spontaneously move away from moisture or wet conditions: There are some ahydrotaxes in nature that are intolerant of or can't exist very long in water or even in prolonged wet or damp environments.
ahypnia (s) (noun), ahypnias (pl)
Sleeplessness or being unable to sleep: Angelina often had a condition of ahypnia that resulted in keeping her from sleeping, so she had to take sleeping pills on many occasions.

There are many people who are suffering from various forms of ahypnia.

alalia (s) (noun), alalias (pl)
Speechlessness; loss of the ability to talk: As a result of an earlier trauma, Muriel had to live with alalia and so she learned to communicate by writing instead of speaking.