How strange, a dog getting promises of cash! (7)
I believe the answer is:
curious
'how strange' is the definition.
'curious' can be an answer for 'strange' (similar in meaning). I'm not certain of the 'how' bit.
'a dog getting promises of cash' is the wordplay.
'a dog' becomes 'cur' (a cur is an aggressive or scruffy dog).
'getting' means one lot of letters go next to another.
'promises of cash' becomes 'ious' (I can't justify this - if you can you should believe this answer much more).
'cur'+'ious'='CURIOUS'
Can you help me to learn more?
(Other definitions for curious that I've seen before include "Eager to learn, strange" , "Strange - inquisitive" , "Questioning" , "Intrigued" , "Odd or eager to know" .)