ETYM Old Eng. darien, to lie hidden, be timid.
To be courageous enough to try or do something:.
1. To get to or be allowed to do something; SYN. can, get.
2 — used in auxiliary function to express a wish or desire especially in prayer, imprecation, or benediction
3 — used in auxiliary function expressing purpose or expectation or contingency or concession or choice
4. Shall, must — used in law where the sense, purpose, or policy requires this interpretation