Sentence:  [stanza I] A Gentle Knight was pricking on the Plain, / Yclad in mightie Arms and ſilver Shield, ... / [stanza II] And on his Breaſt a bloody Croſs he bore, / The dear <WSD>remembrance</WSD> of his dying Lord, / For whoſe ſweet ſake that glorious Badge he wore, / And dead (as living) ever him ador'd: ... 
Meaning of the word marked with <WSD> tags:  That which serves to keep in or bring to mind; a memento, a memorial, a souvenir, a token; a memorandum or note of something to be remembered.