porter has 13 distinct synonyms spread across 6 of its 8 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.
someone who guards an entrance
United States writer of novels and short stories (1890-1980)
United States composer and lyricist of musical comedies (1891-1946)
United States writer of short stories whose pen name was O. Henry (1862-1910)
a railroad employee who assists passengers (especially on sleeping cars)
carry luggage or supplies
“They portered the food up Mount Kilimanjaro for the tourists”
Synonyms, antonyms and the broader and narrower relations for porter come from Princeton University’s WordNet. Full sources and licences.