Speak up over His Majesty: King supporting a cover-up (7)
I believe the answer is:
yashmak
'cover-up' is the definition.
(veil worn by some Muslim women)
'speak up over his majesty king supporting a' is the wordplay.
'speak up' becomes 'say' (I've seen this before. I am not sure about the 'up' bit.).
'over' says the letters should be written in reverse.
'his majesty' becomes 'hm' (short for His Majesty).
'king' becomes 'K' (abbreviation for king in chess).
'supporting' means one lot of letters go next to another (in a down clue, some letters go below others).
'say' reversed gives 'yas'.
'k' after 'a' is 'ak'.
'yas'+'hm'+'ak'='YASHMAK'
Can you help me to learn more?
(Other definitions for yashmak that I've seen before include "modest assumption" , "Face-veil for Muslim women like shaky ma" , "Face-veil worn by Muslim women" , "Am shaky about face-veil for Muslim woman" , "Moslem woman's double veil" .)