syntagm vs linguistic string

syntagm and linguistic string both are nouns.

Word	Noun	Adjective	Verb	Adverb
syntagm	Yes	No	No	No
linguistic string	Yes	No	No	No

As nouns, linguistic string is a hypernym of syntagm; that is, linguistic string is a word with a broader meaning than syntagm:

syntagm: a syntactic string of words that forms a part of some larger syntactic unit
linguistic string: a linear sequence of words as spoken or written

Other hypernyms of syntagm include string of words, word string.

syntagm (noun)	linguistic string (noun)
a syntactic string of words that forms a part of some larger syntactic unit	a linear sequence of words as spoken or written