Clue: Weather-beaten centenarian associated with endless Rime? (7,7)
Answer: ANCIENT MARINER
Explanation: Definition: Weather-beaten centenarian associated with endless Rime?
***(centenarian rim) **[anag:*weather-beaten*] where RIM is [*endless*] RIME(e) 
*I don't know how old the Ancient Mariner was in Coleridge's poem, but I doubt he was 100!