Dogs appear to have eaten promissory note - how strange (7)
I believe the answer is:
curious
'strange' is the definition.
(similar in meaning)
'dogs appear to have eaten promissory note' is the wordplay.
I cannot really see how this works, but
'note' could be 'iou' (I owe you, a promise to pay a debt) and 'iou' is located in the answer.
'dogs' could be 'curs' (cur can mean a violent dog) and 'curs' is found within the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
'how' acts as a link.
Can you help me to learn more?
(Other definitions for curious that I've seen before include "Eager to know something, perhaps nosy" , "Intrigued" , "Eager to know; strange" , "Keen to learn" , "Strange, unusual" .)