I. trea ‧ sure 1 /ˈtreʒə $ -ər/ BrE AmE noun
[ Date: 1100-1200 ; Language: Old French ; Origin: tresor , from Latin thesaurus , from Greek thesauros ]
1 . [uncountable] a group of valuable things such as gold, silver, jewels etc
buried/hidden/sunken treasure
2 . [countable] a very valuable and important object such as a painting or ancient document:
The Book of Kells is Trinity College’s greatest treasure.
3 . [singular] informal someone who is very useful or important to you:
Our housekeeper is a real treasure.
II. treasure 2 BrE AmE verb [transitive]
to keep and care for something that is very special, important, or valuable to you:
Jim treasured the gold pocket watch that his grandfather had given him.
—treasured adjective [only before noun] :
A battered old guitar was his most treasured possession.