Half missed moment Hal without king makes entrance (7)
I believe the answer is:
enthral
'entrance' is the definition.
(I've seen this before)
'half missed moment hal without king' is the wordplay.
'half missed' suggests halving the letters.
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'king' becomes 'r' (r is abbreviation for rex).
'moment' cut in half is 'ent'.
'hal' going around 'r' is 'hral'.
'ent'+'hral'='ENTHRAL'
'makes' acts as a link.
(Other definitions for enthral that I've seen before include "Hold captive" , "Fascinate - grip" , "yoke" , "Hold spellbound" , "Bewitch" .)