Real Dictionary

conserve
variable noun: Conserve is jam containing a large proportion of fruit, usually in whole pieces.
verb: If you conserve a supply of something, you use it carefully so that it lasts for a long time.
verb: To conserve something means to protect it from harm, loss, or change.

conserve in American English
a kind of jam made of two or more fruits, often with nuts or raisins added
to keep from being damaged, lost, or wasted; save
noun: a mixture of several fruits cooked to jamlike consistency with sugar and often garnished with nuts and raisins
transitive verb: to prevent injury, decay, waste, or loss of

conserve in British English
noun: a preparation of fruit in sugar, similar to jam but usually containing whole pieces of fruit
verb: to keep or protect from harm, decay, loss, etc