the GNU version of the Collaborative International Dictionary of English
adj. Not compressible; incapable of being reduced by force or pressure into a smaller compass or volume; resisting compression.
The Century Dictionary and Cyclopedia
Not compressible; incapable of being reduced in volume by pressure.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. incapable of being compressed; resisting compression
Word Usage
"If I read it right, he’s claiming that IC structures are, according to information theory, necessarily random in your #2 sense of incompressible, which is clearly at odds with reality."