Texan mission (5)
I believe the answer is:
alamo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">texan mission</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for alamo that I've seen before include "Fort in San Antonio, once famously besieged" , "Scene of massacre in Texas" , "US mission" , "Famous battle site in Texas" , "Texas mission taken by Mexican forces in 1836" .)