Man needs a second Texas landmark (5)
I believe the answer is:
alamo
'texas landmark' is the definition.
(I've seen this in another clue)
'man needs a second' is the wordplay.
'man' becomes 'Al' (man's name).
'needs' means one lot of letters go next to another.
'second' becomes 'mo' (both are short periods of time).
'al'+'a'+'mo'='ALAMO'
(Other definitions for alamo that I've seen before include "The answer is a place of siege" , "Famous Texan mission" , "Texan battle" , "Famous battle in Texas launched by the Mexican army" , "Famous battle site in Texas" .)