tb has 9 distinct synonyms spread across 5 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.
a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite
infection transmitted by inhalation or ingestion of tubercle bacilli and manifested in fever and small lesions (usually in the lungs but in various other parts of the body in acute stages)
a unit of information equal to 1000 gigabits or 10^12 (1,000,000,000,000) bits
a unit of information equal to 1000 gigabytes or 10^12 (1,000,000,000,000) bytes
a unit of information equal to 1024 gibibytes or 2^40 (1,099,511,627,776) bytes
Synonyms, antonyms and the broader and narrower relations for tb come from Princeton University’s WordNet. Full sources and licences.