Nonsense, gibberish, or gobbledygook was something such as speech, writing, behavior, an opinion, idea, or any other concept which lacked coherent meaning or was foolish.
In 1968, a nuclear warhead was placed in sub-orbit of Earth by a major power and the United States in response planned to launch a suborbital platform with multi-warhead capacity to maintain the balance of power. Gary Seven stated that was the same kind of nonsense that almost destroyed the planet Omicron IV. (TOS: "Assignment: Earth")
In 2364, Q, wearing a 20th century United States Marine Corps uniform, told Captain Jean-Luc Picard that patriotism was at stake and that Picard must return to Earth and put an end to the communists. Picard noted such nonsense was centuries behind them. After Q had put the crew of the USS Enterprise-D on trial to answer for the savageries of their species, Lieutenant Commander Data objected due to a 2036 United Nations declaration that no Earth citizen could be made to answer for the crimes of their race or forebears. Q denied the objection as it was a court of 2079, by which time all United Earth nonsense had been abolished. (TNG: "Encounter at Farpoint")
In 2373, Captain Kathryn Janeway guessed that no one else in the universe would have Q as a mate after he chose her. Q called the statement nonsense as he could have also chosen a Klingon targ, the Romulan empress, or a Cyrillian microbe. (VOY: "The Q and the Grey")