2. fickle glass: ever-changing hourglass.
3. by waning grown: grown more beautiful with the passage of time.
4. withering: fading, decaying. lit. and fig.
5. wrack: ruin; decay. i.e., Nature is mistress of decay because all living in Nature are born to die and death is the true beginning of wrack and ruin.
6. still: continually.
8. minutes kill: i.e., to render powerless the passage of minutes.
9. minion: darling; favorite.
10. still: always and forever.
11. audit: final accounting. answer'd: settled; paid.
12. quietus: (1) a release or respite from life; an ending of life, death; something that causes death. (2) Means of settlement; discharge; quittance. (3) A thing that has a quietening or soothing effect; a salve, a sedative. render: surrender.