WordNet records no synonym and no antonym for poet laureate. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a poet who is unofficially regarded as holding an honorary position in a particular group or region
“she is the poet laureate of all lyricists”
Synonyms, antonyms and the broader and narrower relations for poet laureate come from Princeton University’s WordNet. Full sources and licences.