Get out the microscope, because we’re going through this poem line-by-line.
Then be not coy, but use your time,
And while ye may, go marry:
- Since youth is fleeting, old age sucks, and death is always right around the corner, the speaker urges the virgins to make use of what they have ("use your time") while they still can.
- In other words, don't be "coy," meaning shy, reserved, or inactive.
- The speaker doesn't just encourage the virgins to "use" their time, but to "go marry" (as in, to go get married!) while they still can.
- So this whole time – all that stuff about death being close, youth being short – the speaker's been gearing up to talk about marriage? Yes indeedy.
For having lost but once your prime
You may for ever tarry.
- The virgins should get married, the speaker suggests, because once they lose their "prime" (i.e., their youth and beauty) they might not get another chance.
- "Tarry" means "delay" or "prolong," and here the speaker wants to imply that if the virgins don't get married while they can, they might put it off (marriage) forever!