The most common and most likely answer to this crossword clue is the 2 plus 7 letter word AD NAUSEAM
I've seen this crossword clue in Independent
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More clues leading to the result AD NAUSEAM
- Commercial exploitation’s closing gold mining resource with wearying regularity
- Plug new gold vein until all are bored
- Made sauna boiling time after time
- Endlessly repeated thus, commercial has rebranded a US name
- Amanda and Sue skipping till sickness strikes
- Sauna made boiling until one was sick
- AA named us in error time after time
- A sundae ordered in the morning, enough to make you sick?
- A day going over Northern Australia upset Miss West to the point of sickness
- A code for life: manipulate a male until bored
Buddy explains!

The straight part
We know that "until bored" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case until bored = ad nauseam.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.