shoe string vs shoestring

shoe string and shoestring both are nouns.

Word	Noun	Adjective	Verb	Adverb
shoe string	Yes	No	No	No
shoestring	Yes	No	No	No

As nouns, shoe string and shoestring are synonyms defined as:

Other synonyms of shoe string include shoe lace, shoelace.

As nouns, shoe string and shoestring are synonyms defined as:

shoe string (noun)	shoestring (noun)
a lace used for fastening shoes	a lace used for fastening shoes
a small amount of money	a small amount of money