Former chief designed old Rover (8)

I believe the answer is:

overlord

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'former chief' is the definition.
'overlord' can be an answer for 'chief' (thesaurus). I am not certain of the 'former' bit.

'designed old rover' is the wordplay.
'designed' is an anagram indicator (designed with the letters).
'old'+'rover'='oldrover'
'oldrover' anagrammed gives 'OVERLORD'.

Can you help me to learn more?

(Other definitions for overlord that I've seen before include "WWII Operation" , "Boss" , "top man!" , "Ruler, D-day Operation" , "Supreme ruler" .)

I've seen this clue in the Irish Times and the Irish Times (Crosaire).

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