If "try out" refers to testing something:
* Discard: This implies rejecting something after trying it.
* Reject: Similar to "discard", but with a stronger implication of disapproval.
* Abandon: This implies giving up on something entirely.
* Ignore: This suggests not even bothering to try something.
If "try out" refers to auditioning for something:
* Decline: This means to refuse an offer to participate.
* Pass on: This is a more casual way of saying "decline".
* Turn down: Similar to "decline" but with a stronger implication of rejection.
If "try out" refers to experimenting:
* Stick with: This implies continuing with a known method or approach.
* Stay with: Similar to "stick with", but with a stronger implication of commitment.
* Settle for: This implies accepting something less desirable rather than trying something new.
Ultimately, the best antonym for "try out" depends on the specific context and the nuance you want to convey.