In short, the sunny area familiar to travellers (3)
I believe the answer is:
med
'in' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for med that I've seen before include "Mediterranean (colloq.)" , "Cote d'Azur sea" , "Sea (informal)" , "Sea (abbr)" .)