Semantics was a branch of linguistics that focused on the meaning of words and phrases.
Semantics was a field of study in which Ensign Sonya Gomez believed that Jean-Luc Picard was knowledgeable. When Wesley Crusher was wondering what he might talk to the captain about on their long shuttlecraft journey to Starbase 515, Gomez suggested it as an interesting topic of conversation. (TNG: "Samaritan Snare")
In 2369, Ilon Tandro dismissed the fact that the warrant issued for "Dax" applied to Curzon Dax, not Jadzia Dax as semantics. (DS9: "Dax")
In 2372, Neelix had no use for Tuvok's semantics when the Vulcan rebuffed the Talaxian's enthusiasm and observations on his character. (VOY: "Tuvix")
Around 3074, a simulated Kathryn Janeway saw little difference between defeat and genocide. (VOY: "Living Witness")