Obstruction blocking way? You can bet on it (8)
I believe the answer is:
roulette
'you can bet on it' is the definition.
I can't tell whether this definition defines the answer.
'obstruction blocking way?' is the wordplay.
'obstruction' becomes 'let' (I've seen this in other clues).
'blocking' indicates putting letters inside.
'way?' becomes 'route' (route is a kind of way).
'let' placed within 'route' is 'ROULETTE'.
Can you help me to learn more?
(Other definitions for roulette that I've seen before include "Spinning-wheel game" , "risky venture" , "Table game" , "Wheel of fortune" , "Gambling game with small ball and revolving disc (8)" .)