The childless total frequently is high (5)
I believe the answer is:
aloft
'high' is the definition.
(I've seen this in another clue)
'the childless total frequently' is the wordplay.
'the childless total' becomes 'al' (I can't justify this - if you can you should believe this answer much more).
'frequently' becomes 'oft' (oft can mean frequently, eg oft-quoted).
'al'+'oft'='ALOFT'
'is' acts as a link.
Can you help me to learn more?
(Other definitions for aloft that I've seen before include "Skyward" , "at high altitude" , "To great height" , "In the rigging, up high" , "Float (anag.)" .)