"Embroidered was he..."
See in text (The General Prologue - The Squire)
This means that the Squire is wearing a tunic with a red and white cross on it. However, the syntax of this description metaphorically “embroiders” the squire himself with “red and white,” making the squire synonymous with the symbol he wears.
"could make a crown..."
See in text (The General Prologue - The Merchant)
In other words, he was so good with money that he could have been a king of it. Chaucer uses this metaphor to compare the Merchant's activities with those of a king. The Merchant is one of the first characters who seems to fit his vocation as well as the [Knight] (http://www.owleyes.org/read/canterbury-tales/the-knight).
"bragget or as mead..."
See in text (The Miller’s Tale)
The Blazon was a poetic tradition of the chivalric romance that defined a woman's perfection by focusing on each part of her body and comparing it to something pure. For example, her skin as white as snow. Here, the Miller uses the same poetic catalogue to describe the carpenter's wife. However, instead of comparing her to pure or elegant things, he compares her to common items associated with the low classes, such as mead.
See in text (The Wife of Bath’s Prologue)
"Leaf" in this context means a page within a book. Alison, the Wife of Bath, is talking about tearing a page out of a book that her husband owns. Metaphorically, this signifies that she is challenging his authority, since in Chaucer's time men controlled learning and women were generally illiterate. To punish her, the Wife's husband hits her in the ear and causes her to go deaf.
"wheat and let the chaff..."
See in text (The Nun’s Priest’s Tale)
This is a metaphor that compares the story to wheat and its chaff. In much the same way one separates wheat, which can be made into bread, from its chaff, or covering, the moral of this story can be separated out from the narrative story around it. This is an interesting narrative device because the Nun's Priest offers this metaphor rather than explicitly telling the audience what the moral message of the story was.