Expectation was a belief or idea about what would likely happen.
In 2368, Worf's spinal cord was crushed and he was left paralyzed. Doctor Beverly Crusher welcomed Captain Jean-Luc Picard to visit Worf in sickbay, but told him not to expect a lot of conversation as Worf was in "full Klingon mode;" honorable, strong, and closed-minded. (TNG: "Ethics")
In 2375, Seven of Nine told One, a Borg drone who had been created aboard the USS Voyager and gained individuality through an unusual confluence of events, that he had exceeded the expectations of those aboard the vessel. In response, he stated that those expectations were insufficient, but she stated that a simple "thank you" would suffice. (VOY: "Drone")