There are a few new words in this poem that I looked up.
Halcyon sea - It means peaceful sea.
Vair - This is a type of squirrel fur.
Dias - A raised platform in a large room that people stand on to speak in front of an audience.
My heart is like a singing bird
Whose nest is in a water'd shoot;
My heart is like an apple-tree
Whose boughs are bent with thickset fruit;
My heart is like a rainbow shell
That paddles in a halcyon sea;
My heart is gladder than all these
Because my love is come to me.
Raise me a dais of silk and down;
Hang it with vair and purple dyes;
Carve it in doves and pomegranates,
And peacocks with a hundred eyes;
Work it in gold and silver grapes,
In leaves and silver fleurs-de-lys;
Because the birthday of my life
Is come, my love is come to me.