|least recently used - (operating systems) (LRU) A rule used in a paging system
which selects a page to be paged out if it has been used
(read or written) less recently than any other page. The same
rule may also be used in a cache to select which cache entry
This rule is based on temporal locality - the observation that, in general, the page (or cache entry) which has not been accessed for longest is least likely to be accessed in the near future.