To defer something means to put it off, or to leave it until a later date.
If you defer a dream, or something that you really want to do, you are never able to achieve it. Instead of being able to live out your dream – owning a business, becoming an actor or artist, traveling the world, etc. – you settle for something else.
This can be because you never felt secure or sure enough to pursue your dream, or simply let the daily responsibilities that you have guide you away from your dream.
For anyone, a dream deferred may always stay like that – a dream, rather than something that you can actually have.
