Wet track limits Asians every so often (5)
I believe the answer is:
rainy
'wet' is the definition.
(similar in meaning)
'track limits asians every so often' is the wordplay.
'track' becomes 'RY' (abbreviation for railway).
'limits' means one lot of letters goes inside another (limit can mean to contain or block off).
'every so often' indicates alternate letters.
The alternate letters of 'asians' are 'ain'.
'ry' enclosing 'ain' is 'RAINY'.
(Other definitions for rainy that I've seen before include "With water falling outside" , "Drizzly" , "Save your money for this damp day" , "Save your money for a . . . . . day - to buy an umbrella?" , "(Of weather) wet" .)