Parent losing head - something else! (5)
I believe the answer is:
other
'something else' is the definition.
(another thing)
'parent losing head' is the wordplay.
'parent' becomes 'mother' (mother is a kind of parent).
'losing head' means to remove the first letter.
'mother' with its initial letter taken off is 'OTHER'.
(Other definitions for other that I've seen before include "Very unusual" , "Second" , "Different, not the same one or this one" , "Alternative - unrelated" , "Different, disparate" .)