A used book, one which may include physical wear, highlighting or marginalia and hence lacks value as a collectible, but which remains in sufficiently good condition to be suitable for someone whose primary interest is in reading the book.

(Internet) A copy of an email message that is sent to a person (often one of many) other than the primary recipient without the express knowledge of the other recipients.

plural of carbonless copy paper

(programming) A proxy that controls the copying of an object by deferring the copy until it is required by a client.

plural of copy-on-write proxy

(genetics) A DNA sequence, 1000 nucleotides (or synonymously base pairs) in length or longer, that is present a variable number of times as copies in a genome relative to a reference genome.

(genetics) The variation of the number of copies (normally two) of a gene, or of sequences of DNA, in the genome of a specific individual; has been linked to some diseases

(genetics) The normal variation in the number of copies (normally two) of a gene, or of sequences of DNA, in the genome of a specific individual

A form of paper that is coated with a substance on the reverse and so does not need a separate sheet of carbon paper in order to produce copies

plural of blind carbon copy