Cynicism was a lack of trust in others' motives.
In 2024, Christopher Brynner excused Jadzia Dax's cynicism about whether San Francisco would experience protests by saying she'd been mugged. (DS9: "Past Tense, Part I")
In 2151, Captain Jonathan Archer told a disapproving T'Pol to bury her Vulcan cynicism along with her repressed emotions. (ENT: "Broken Bow")
Later that year, Silik criticized Archer's cynicism when the captain speculated on what genetic enhancements the Suliban would get as a reward for bringing back a Temporal Observatory. (ENT: "Cold Front")
Upon hearing Malcolm Reed record a letter to his parents in the event of his death, which Reed believed imminent, Trip Tucker interrupted the missive to ask them if Reed was always that cynical. (ENT: "Shuttlepod One")
In 2153, when Tucker suggested Fuller's death would not be the last one on Enterprise NX-01, Reed told him there was no reason to get cynical. (ENT: "Anomaly (ENT)")
In 2154, after Archer assured her that there would be a lot of battles ahead, Hernandez suggested he was being cynical. (ENT: "Home")
In 2371 of the the mirror universe, Kira Nerys attributed Elim Garak's uncovering Benjamin Sisko's plans to the Cardassian's cynicism. (DS9: "Through the Looking Glass")
When Sisko suggested Dukat was relieved at Tekeny Ghemor's death, the gul replied that "such cynicism does not suit you". (DS9: "Ties of Blood and Water")
In 2375, amused by Garak's low view of the possibility of peace with the Romulans, Julian Bashir replied, "Well, I shall endeavour to become more cynical with each passing day, look gift horses squarely in the mouth and find clouds in every silver lining." (DS9: "Inter Arma Enim Silent Leges")
In 2376, Neelix explained to Dala that while he originally hoped to profit from his time on USS Voyager, he realized he preferred helping to being "self-serving and cynical". (VOY: "Live Fast and Prosper")
In 2378, a younger version of Kathryn Janeway didn't want to believe she'd be as cynical as her older admiral self, after the elder Janeway believed she would be taken to sickbay and sedated. (VOY: "Endgame")
In 3189, Gabrielle Burnham argued against Michael Burnham, saying, "She's asking this Quorum to take what she says on faith. She demands trust while her own actions are cynical." (DIS: "Unification III")