A cliché was a phrase or action that had become overused to the point of making users of the phrase seem to lack imagination or be boring.
Stephen G. Richey's assessment of the novel Hotel Royale was that it was rife with "endless clichés and shallow characters". As a result, he looked forward to death after being subjected to living in a world created for him using the book as a reference. (TNG: "The Royale")
In 2366, after placing himself in harm's way to save the crew of the USS Enterprise-D, a Human-ized Q referred to Jean-Luc Picard's penchant for pulling off a rescue at the last minute as a tired cliché, urging him not to do so in this case, hoping to gain dignity through self-sacrifice that he had failed to achieve in Human form until then. (TNG: "Deja Q")
Prior to becoming a tailor, Garak lived by the motto "Never let sentiment get in the way of your work." Though a cliché, he found there was truth to the saying. He used this motto to justify killing Quark in 2370 when the Ferengi had gotten in too deep. (DS9: "Profit and Loss")