memory has 9 distinct synonyms spread across 3 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. 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.
something that is remembered
“search as he would, the memory was lost”
the cognitive processes whereby past experience is remembered
“he can do it from memory”
the power of retaining and recalling past experience
“he had a good memory when he was younger”
an electronic memory device
“a memory and the CPU form the central part of a computer to which peripherals are attached”
the area of cognitive psychology that studies memory processes
“he taught a graduate course on learning and memory”
Synonyms, antonyms and the broader and narrower relations for memory come from Princeton University’s WordNet. Full sources and licences.