What does Leviathan mean?
Hebrew livyathan, a great sea-serpent/monster, generally glossed 'twisted, coiled' and derived (per Gesenius) from the root l-w-h 'to twine, wind' with a suffix, i.e. 'wreathed one'. Flag: the derivation is disputed (some hold it a loanword), and in use it is the name of a biblical serpent-monster; the 'coiled serpent' sense is the established reading.
What does Ophir mean?
Biblical place name (אוֹפִיר) for a region famed as a source of fine gold; popularly glossed 'gold' as a given name. Flagged: the Hebrew root itself is of uncertain derivation, so 'gold' derives from the place's reputation for gold rather than a literal word for the metal — it is a place name / 'gold-rich' byname.