Also right! Turn around and measure developmental steroid (8)
I believe the answer is:
androgen
'developmental steroid' is the definition.
'androgen' can be an answer for 'steroid' (androgen is a kind of steroid). I'm not sure about the 'developmental' bit.
'also right turn around and measure' is the wordplay.
'also' becomes 'and' (I've seen this before).
'right turn around' becomes 'rog' (I can't justify this - if you can you should believe this answer much more).
'and' means one lot of letters go next to another.
'measure' becomes 'en' (typographical measure).
'and'+'rog'+'en'='ANDROGEN'
Can you help me to learn more?
(Other definitions for androgen that I've seen before include "Male hormone" , "Steroid" .)