Definition 4: 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) - [noun denoting state]
(... is a kind of tb ) acute tuberculosis characterized by the appearance of tiny tubercles on one or more organs of the body (presumably resulting from tubercle bacilli being spread in the bloodstream)
Definition 5: a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite - [noun denoting substance]
(tb is a kind of ...) any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
(... is made of the substance tb) a common complex mineral consisting of calcium fluoride phosphate or calcium chloride phosphate; a source of phosphorus
(... is made of the substance tb) a mineral that is a source of rare earths; consists of silicates of iron and beryllium and cerium and yttrium and erbium