What does deathless mean?

The word "[deathless](http://www.accesstoinsight.org/search_results.html?cx=015061908441090246348%3Adj4lxnh4dda&cof=FORID%3A9%3BNB%3A1&ie=UTF-8&q=deathless&sa=Search) " is used sometimes. What does it mean? Are there non-obvious or non-English meanings to the words translated as 'death' and/or 'deathless'? Similarly what does "attaining the deathless" mean, in this [Upatissa-pasine](http://www.accesstoinsight.org/tipitaka/vin/mv/mv.01.23.01-10.than.html) , for example ... > Whoever attains the Deathless first will inform the other ... how are they supposed to recognize when they "attain the deathless"? Is "deathless" predicated on the idea that practitioners are trying to escape some dukkha associated with death, or escape death itself? Does that sutta conflate "deathless" with "sorrowless", or are the two distinct? I notice there's also a word [Timeless](https://buddhism.stackexchange.com/a/8092/254) . Deathless is a different word (*amata* instead of *akalika*), does the word 'deathless' have a different meaning and/or different usage? --- The expression is used in the [Ariyapariyesana Sutta](http://www.accesstoinsight.org/tipitaka/mn/mn.026.than.html) : > So I said to them, 'Don't address the Tathagata by name and as "friend." The Tathagata, friends, is a worthy one, rightly self-awakened. Lend ear, friends: the **Deathless** has been attained. That suggests to me (I may be wrong) that deathless might be associated with an ultimate stage of enlightenment (or perhaps that it's specifically intended/designed for the five in that audience, e.g. perhaps the Buddha knew that they were seeking "the deathless").