sampler has 4 distinct synonyms spread across 2 of its 4 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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.
an observation station that is set up to make sample observations of something
someone who samples food or drink for its quality
Synonyms, antonyms and the broader and narrower relations for sampler come from Princeton University’s WordNet. Full sources and licences.
an assortment of various samples
“a candy sampler”
a piece of embroidery demonstrating skill with various stitches