The answer to each clue is a 3-, 6-, or 9-letter word. If you split these into 3-letter chunks, you will find 20 different ‘triples’ each appearing twice.

For example if one answer was ‘bellow’ then ‘bel’ and ‘low’ would appear somewhere else too, for instance in ‘disbelief’ and ‘lowest’, but then ‘dis’, ‘ief’ and ‘est’ would have to appear somewhere else too, etc, until all triples have appeared exactly twice.

Age

Be present at

Christian religious leader

Condensed water droplets

Endurable

Finish

Imperfections

'In the name of Allah'

Mold

Opinion, recommendation

Outcast

Part of a circle

Part of speech

Part of triple jump

Set upon

Shiite religious leader

Softcover

Suitable for purpose

Tropical fruit

Underneath the ...

Vanilla ..., rapper