intelligence has 8 distinct synonyms spread across 4 of its 5 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 stupidity.
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.
the ability to comprehend; to understand and profit from experience
a unit responsible for gathering and interpreting information about an enemy
secret information about an enemy (or potential enemy)
“we sent out planes to gather intelligence on their radar coverage”
the operation of gathering information about an enemy
Synonyms, antonyms and the broader and narrower relations for intelligence come from Princeton University’s WordNet. Full sources and licences.