Let me not to the marriage of true minds
Admit impediments; love is not love
admit=allow to enter
impediments=objections, as at a marriage ceremony
Which alters when it alteration finds,
Or bends with the remover to remove:
bends with=allies with/conforms to
O, no, it is an ever-fixèd mark,
That looks on tempests and is never shaken;
It is the star to every wand'ring bark,
star=North Star
bark=sailing ship
Whose worth's unknown, although his height be taken.
Whose=the star's
height=angle above the horizontal (used in navigation)
Love's not Time's fool, though rosy lips and cheeks
Within his bending sickle's compass come;
sickle=curved tool for cutting grass or crops
compass=tool for drawing circles
Love alters not with his brief hours and weeks,
with=within
his=Time's
But bears it out even to the edge of doom.
doom=death (also, the Last Judgment)
If this be error and upon me proved,
I never writ, nor no man ever loved.
writ=wrote