li·bel 
(lībəl)
(lībəl)n.
1.
a. The legally indefensible publication or broadcast of words or images that are degrading to a person or injurious to his or her reputation.
b. An incidence of such publication or broadcast.
2. The written claims initiating a suit in an admiralty court.
tr.v. li·beled, li·bel·ing, li·bels or li·belled or li·bel·ling
To publish or broadcast a libel about (a person). See Synonyms at malign.
[Middle English, litigant's written complaint, from Old French, from Latin libellus, diminutive of liber, book.]
libel·er, libel·ist n.