Crossword Genius

Base one? Good lord! (7)

Ross

I believe the answer is:

ignoble

'base' is the definition.
(similar in meaning)

'one? good lord' is the wordplay.
'one?' becomes 'I' (Roman numeral).
'good' becomes 'g' (abbreviation).
'lord' becomes 'noble' (synonyms).
'i'+'g'+'noble'='IGNOBLE'

(Other definitions for ignoble that I've seen before include "Not honourable in character or purpose" , "Unworthy" , "Cheap" , "Inferior" , "'Dishonourable, mean (7)'" .)

I've seen this clue in The Sun and The Telegraph.
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