Texan landmark has article by the French doctor (5)
I believe the answer is:
alamo
'texan landmark' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'article by the french doctor' is the wordplay.
'article' becomes 'a' (the indefinite article in English).
'by' means one lot of letters go next to another.
'the french' becomes 'la' ('the' in French).
'doctor' becomes 'mo' (medical officer).
'a'+'la'+'mo'='ALAMO'
'has' acts as a link.
Can you help me to learn more?
(Other definitions for alamo that I've seen before include "Site of a Texas siege, 1836" , "Historic Texas mission station" , "Texas fort, scene of famous siege by Mexican army" , "Fort in San Antonio, once famously besieged" , "US mission" .)