Perhaps solemnly (or appearing so); who? silly, stupid (8)
I believe the answer is:
owlishly
'perhaps solemnly or appearing' is the definition.
I can't tell whether this defines the answer.
'who? silly stupid' is the wordplay.
'stupid' is an anagram indicator (in a stupid order).
'who'+'silly'='whosilly'
'whosilly' is an anagram of 'OWLISHLY'.
'so' acts as a link.
Can you help me to learn more?
(Other definitions for owlishly that I've seen before include "blinking in this fashion?" , "with wise or solemn manner" .)