\text{\oe}
The ligature 'œ' is a typographic character that combines the letters 'o' and 'e'. It is used in some French words and other languages that have borrowed from French. In LaTeX, it is represented by the command \text{\oe}.
The French word for 'heart', using the ligature 'œ'.
C\oe ur
The French word for 'sister', using the ligature 'œ'.
s\oe ur
The French word for 'beef', using the ligature 'œ'.
b\oe uf