### Clue: Rock resident, ancient character brought up on principle of thrift (5)
### Answer: MAGOT 
 ### Explanation: Definition: Rock resident
Reverse of OGAM (Pictish/Celtic character) + T[hrift]. I briefly, though implausibly, suspected Azed of confusing "principle" and "principal", but Chambers gives "a source, root, origin" as its first definition of the former