(rand-nth coll)
Return a random element of the (sequential) collection. Will have the same performance characteristics as nth for the given collection.
user=> (def food [:ice-cream :steak :apple])
#'user/food
user=> (rand-nth food)
:apple
user=> (rand-nth food)
:ice-cream
user=> (def food [:ice-cream :steak :apple])
#'user/food
user=> (rand-nth food)
:ice-cream
user=> (rand-nth food)
:ice-cream