Dictionary.com
Thesaurus.com

lignum vitae

American  
[lig-nuhm vahy-tee, vee-tahy] / ˈlɪg nəm ˈvaɪ ti, ˈvi taɪ /

noun

  1. either of two tropical American trees, Guaiacum officinale or G. sanctum, of the caltrop family, having very hard, heavy wood.

  2. the wood of such a tree, used for making pulley blocks, mallet heads, bearings, etc.

  3. any of several other trees yielding a similar hard wood.


lignum vitae British  
/ ˈlɪɡnəm ˈvaɪtɪ /

noun

  1. either of two zygophyllaceous tropical American trees, Guaiacum officinale or G. sanctum, having blue or purple flowers

  2. the heavy resinous wood of either of these trees, which is used in machine bearings, casters, etc: formerly thought to have medicinal properties

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of lignum vitae

1585–95; < New Latin, Late Latin, name of the tree, literally, wood of life