There is nothing wrong with your spelling.
Main Entry:
her·o·ine
Pronunciation: \ˈher-ə-wən, ˈhir-, ˈhe-rə-\
Function:
noun
Etymology: Latin
heroina, from Greek
hērōinē, feminine of
hērōs
Date: 1609
1 a : a mythological or legendary woman having the qualities of a hero
b : a woman admired and emulated for her achievements and qualities
2 a : the principal female character in a
[COLOR=green! important][COLOR=green! important]literary[/COLOR][/COLOR] or dramatic
work b : the central female figure in an event or period.
The drug is heroin.