Order stout that's rich in a manner of speaking (7)
I believe the answer is:
orotund
'rich in a manner of speaking' is the definition.
I can't judge whether this definition defines the answer.
'order stout' is the wordplay.
'order' becomes 'o' (abbreviation e.g. in British honours OM, OBE etc.).
'stout' becomes 'rotund' (I've seen this before).
'o'+'rotund'='OROTUND'
'that's' is the link.
Can you help me to learn more?
(Other definitions for orotund that I've seen before include "Pompous - grandiose" , "Resonant" , "Full, round" , "Full in sound" , "Of speech, dignified and pompous" .)