Monk with top-class clothing, theoretically (1,6)
I believe the answer is:
a priori
'theoretically' is the definition.
(I've seen this before)
'monk with top-class clothing' is the wordplay.
I cannot quite understand how this works, but
'monk' could be 'prior' (I've seen this before) and 'prior' is present in the answer.
'top' could be 'ai' (resembles A1, term for excellent) and 'ai' is found within the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for a priori that I've seen before include "Like reasoning from cause to effect" , "Derived by logic, without observed facts (Latin)" , "How Romans spoke as far as one knows" , "Deductive, from cause to effect - in Latin" , "worked with deductions" .)