Syntactic ambiguity arises when a sentence can have two (or more) different meanings because of the structure of the sentence—its syntax.
sɪntˈæktɪk ˌæmbɪɡjˈuːɪɾi ɚɹˈaɪzᵻz wɛn ɐ sˈɛntəns kæn hæv tˈuː ɔːɹ mˈoːɹ dˈɪfɹənt mˈiːnɪŋz bɪkˈʌz ʌvðə stɹˈʌktʃɚɹ ʌvðə sˈɛntəns—ɪts sˈɪntæks.