Crossword Genius

Prospecting for oil is monotonous (6)

Ross

I believe the answer is:

boring

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'monotonous' is the definition.
(thesaurus)

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(Other definitions for boring that I've seen before include "Tedious, of no interest" , "Making holes" , "like watching paint dry?" , "Tedious, tiresome" , "Tedious and tiring" .)

I've seen this clue in The Irish News.
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