A drug (trade name Trental) used to treat claudication

• Series of 30 requiems, to Roman Catholics
• Believed to increase the flexibility of red blood cells so they can flow through the blood vessels to the legs and feet

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Trental \Tren"tal\, n. [LL. trentale, fr. L. triginta thirty; akin to tres three: cf. OF. trentel. See Three , and cf. Trigintal .] (R. C. Ch.) An office and mass for the dead on the thirtieth day after death or burial. ``Their trentals and their shrifts.'' ...

Wiktionary Word definitions in Wiktionary
n. 1 A Roman Catholic office and mass for the dead on the thirtieth day after death or burial. 2 (context by extension English) A dirge or elegy.