At least a million people have this language (5)
I believe the answer is:
tamil
'this language' is the definition.
(Tamil is an example)
'at least a million people' is the wordplay.
'TAMIL' is hidden within the letters.
However, I am uncertain how the hidden word is indicated.
'have' acts as a link.
Can you help me to learn more?
(Other definitions for tamil that I've seen before include "One in race" , "Dravidian people of India and Sri Lanka" , "Perhaps Indian" , "Language of southern India and Sri Lanka" , "An official language of Sri Lanka" .)