(informal) A vigorous, committed attempt or effort, often in the context of a nearly hopeless situation where failure is expected.

(transitive with at) To make a risky attempt.

(idiomatic) To try or attempt something.

A caution that the activity being described or demonstrated is not safe for ordinary members of the public to attempt.

however hard one tries; despite one's best efforts

Alternative form of try as one may

To experiment in life; to find out what one is capable of.

To be difficult to deal with; annoy.

Synonym of try it on the dog

indicates the importance of persistence in the pursuit of success.