Charlie's one part of frontier? (10)
I believe the answer is:
checkpoint
'part of frontier?' is the definition.
The definition and answer can be both locations as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'charlie's one' is the wordplay.
I cannot quite see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is located in the answer.
'charlie' could be 'c' (phonetic alphabet: alpha, bravo, charlie etc.) and 'c' is found within the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for checkpoint that I've seen before include "Control station" , "Charlie, perhaps" , "Where on inspection one may cross" , "place at international border?" , "place at frontier?" .)