titanium, Ti, atomic number 22 -- (a light strong grey lustrous corrosion-resistant metallic element used in strong lightweight alloys (as for airplane parts); the main sources are rutile and ilmenite)
ti, Cordyline terminalis -- (shrub with terminal tufts of elongated leaves used locally for thatching and clothing; thick sweet roots are used as food; tropical southeastern Asia, Australia and Hawaii)
ti, te, si -- (the syllable naming the seventh (subtonic) note of any musical scale in solmization)