profound has 7 distinct synonyms spread across 3 of its 6 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. Its one recorded opposite is superficial.
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.
showing intellectual penetration or emotional depth
“the differences are profound”
far-reaching and thoroughgoing in effect especially on the nature of something
“the fundamental revolution in human values that has occurred”
situated at or extending to great depth; too deep to have been sounded or plumbed
“the profound depths of the sea”
2 of the 6 recorded senses carry no synonym, antonym or related term, so they are not shown above. Every sense, with its definition and examples, is on the full entry for profound.
Synonyms, antonyms and the broader and narrower relations for profound come from Princeton University’s WordNet. Full sources and licences.