
Originally Posted by
MikeNewYork
Here is the entry for de- from the AHD:
de–
pref.
Do or make the opposite of; reverse: decriminalize.
Remove or remove from: delouse; deoxygenate.
Out of: deplane; defenestration.
Reduce; degrade: declass.
Derived from: deverbative.
[Middle English de-, from Old French de- (from Latin dē-, from, off, apart, away, down, out, completely, from dē) or from Old French des-, out, off, apart, away, completely (from Latin dis-, dis-, and Latin dē-).]
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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2003 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
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Here is the entry from Webster's:
Main Entry: de-
Function: prefix
Etymology: Middle English, from Old French de-, des-, partly from Latin de- from, down, away (from de, preposition) and partly from Latin dis-; Latin de akin to Old Irish di from, Old English tO to -- more at TO, DIS-
1 a : do the opposite of <deactivate> b : reverse of <de-emphasis>
2 a : remove (a specified thing) from <delouse> b : remove from (a specified thing) <dethrone>
3 : reduce <devalue>
4 : something derived from (a specified thing) <decompound> : derived from something (of a specified nature) <denominative>
5 : get off of (a specified thing) <detrain>
6 : having a molecule characterized by the removal of one or more atoms (of a specified element) <deoxy->