One who is down-to-earth about tails being tossed (7)
I believe the answer is:
realist
'one who is down-to-earth' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'about tails being tossed' is the wordplay.
'about' becomes 're' (regarding).
'being tossed' is an anagram indicator.
'tails' with letters rearranged gives 'alist'.
're'+'alist'='REALIST'
Can you help me to learn more?
(Other definitions for realist that I've seen before include "Is alert (anag)" , "One who faces things as they are" , "Practical sort" , "who may look for practical solution" , "Pragmatist" .)