A tidally-locked world should spin on its axis once a year. The net effect is that one side always faces its sun and that the other side always faces the other way. However, there is still an axis of rotation that defines an equator. The names for directions would still apply here because there is spin that defines an equator, a left (sinister in Latin) pole, and a right (dexter in Latin) pole.

Also, note that these concepts are in no way related to any sort of symmetry of the species living on the planet, just the assumption that they can detect the rising and falling of the overhead star field (meaning relatively clear atmospheres and some sort of EM detection system that can resolve stars through that atmosphere).

Please consider xkcd: Fiction Rule of Thumb as a cautionary note.