nonsense

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Words or signs having no intelligible meaning.
• noun Subject matter, behavior, or language that is foolish or absurd.
• noun Extravagant foolishness or frivolity.
• noun Matter of little or no importance or usefulness.
• noun Insolent talk or behavior; impudence.
• adjective Genetics Of or relating to a mutation in a structural gene that changes a nucleotide triplet into a stop codon, thus prematurely terminating the polypeptide chain during protein synthesis.
• interjection Used to express disagreement or exasperation.

from The Century Dictionary.

• noun Not sense; that which makes no sense or is lacking in sense; language or words without meaning, or conveying absurd or ridiculous ideas; absurd talk or senseless actions.
• noun Trifles; things of no importance.
• noun Synonyms Folly, stuff, twaddle, balderdash.

from the GNU version of the Collaborative International Dictionary of English.

• noun That which is not sense, or has no sense; words, or language, which have no meaning, or which convey no intelligible ideas; absurdity.
• noun Trifles; things of no importance.
• noun lines made by taking any words which occur, but especially certain words which it is desired to recollect, and arranging them without reference to anything but the measure, so that the rhythm of the lines may aid in recalling the remembrance of the words.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Letters or words, in writing or speech, that have no meaning or seem to have no meaning.
• noun An untrue statement.
• noun Something foolish.
• noun literature A type of poetry that contains strange or surreal ideas, as, for example, that written by Edward Lear.
• noun biology A damaged DNA sequence whose products are not biologically active, that is, that does nothing.
• verb To make nonsense of
• verb To attempt to dismiss as nonsense.
• verb intransitive To joke around, to waste time

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective having no intelligible meaning
• noun a message that seems to convey no meaning
• noun ornamental objects of no great value