Irrational hesitation after oxygen becomes addictive stuff (5)
I believe the answer is:
opium
'addictive stuff' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'irrational hesitation after oxygen' is the wordplay.
'irrational' becomes 'pi' (an irrational number).
'hesitation' becomes 'um' (um is said in hesitation).
'after' means one lot of letters go next to another.
'oxygen' becomes 'O' (atomic symbol for oxygen).
'pi'+'um'='pium'
'pium' put after 'o' is 'OPIUM'.
'becomes' is the link.
Can you help me to learn more?
(Other definitions for opium that I've seen before include "Dried juice of white poppy" , "Narcotic derived from poppy" , "wars with China" , "De Quincey confessed to eating it" , "Addictive narcotic" .)