A loud "So the interior is below zero" (10)
I believe the answer is:
thunderous
'a loud' is the definition.
(thesaurus)
'the interior is below zero' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'below' could be 'under' (synonyms) and 'under' is located in the answer.
'zero' could be 'o' (O resembles 0) and 'o' is present in the answer.
This explanation may well be incorrect...
'so' is the link.
Can you help me to learn more?
(Other definitions for thunderous that I've seen before include "Loud and rumbling" , "Deafening" .)