Heard luck was turning, as it can be up and down
I believe the answer is:
seesaw
'be up and down' is the definition.
(thesaurus)
'heard luck was turning' is the wordplay.
'heard luck' becomes 'see' (I can't explain this - if you can you should give a lot more credence to this answer).
'turning' says the letters should be written backwards.
'was' in reverse letter order is 'saw'.
'see'+'saw'='SEESAW'
'as it can' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for seesaw that I've seen before include "swing" , "that has its ups and downs" , "Piece of playground equipment" , "Change back and forth rapidly and repeatedly" , "Teeter-totter" .)