Bonded. With the little that Uhura knew about Vulcan culture (mostly what she had learned from him in order to augment her linguistic lessons), she had a very rudimentary understanding of what that meant on the intellectual level, but right now... The way that she could feel the worry that was churning in the back of his mind, the emotions that he was struggling to keep out of his tone, it was hard to really think of that explanation as explaining even half of this.
Settling her hand lightly on his arm, Uhura looked up at him, a soft understanding in her eyes as it reverberated in her mind. There was nothing for him to be scared of or even concerned about. She was...surprised, yes, slightly overwhelmed, of course, but mostly because she was adapting to feeling someone else's thoughts, emotions, sensing them in every aspect. She had memories that weren't here own slowly filtering into her consciousness as the two of them came fuller back into their own minds.
"We never really discussed this at length," Uhura said, her hand gripping his arm lightly as tears started to prick at her eyes, moved by the sheer intensity of everything that she was feeling from him. She had always known that he was more than what he allowed to show on the surface. But this was more than she had ever truly imagined. "But there's nothing for you to worry about," Uhura whispered, tucking her head back against his shoulder. "Nothing at all."