Article on a naval corps has a line which is uplifting (7)
I believe the answer is:
thermal
'article on a naval corps has a line which is uplifting' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'article on a naval corps has a line' is the wordplay.
'article on a naval corps has' becomes 'therm' (I can't explain this - if you can you should believe this answer much more).
'line' becomes 'l' (used when specifying particular lines from a poem).
'therm'+'a'+'l'='THERMAL'
Can you help me to learn more?
(Other definitions for thermal that I've seen before include "Rising current (used by gliders)" , "Updraught for gliders" , "Concerned with high temperature" , "Up-current of air" , "help for glider" .)