Without any clear plan, Henry cut off fire hydrant foolishly (6)

I believe the answer is:

adrift

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'foolishly' is the definition.
Both the answer and definition are adverbs. Perhaps they are linked in a way I don't understand?

I can't explain the remainder of the clue.

Can you help me to learn more?

(Other definitions for adrift that I've seen before include "getting nowhere?" , "Purposeless" , "Disoriented" , "out of touch" , "No longer fixed in position" .)

I've seen this clue in The Irish Times.

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