Enjoyment of Shabbat is important enough that it could override rabbinic decrees: Bava Metzia 54a
Honor of Shabbat - Kevod Shabbat
Note: The focus of Kevod Shabbat is in the preparations done before Shabbat.
Odd: Rashi uses the term "kevod shabbat" in describing a gemara's concern, even though the gemara invokes the biblical pasuk of oneg: Rashi Bava Metzia 54a s.v. "b'shabbat"