sound-symbolic

adjective2

1. •
   characterized by sound symbolism
2. •
   (of a unit of sound or meaning such as a word, morpheme, phoneme, syllable, etc.) composed of speech sounds that are not arbitrary but also not overtly onomatopoeic

   • "Bouba" and "Kiki" are sound-symbolic labels, not directly imitating any actual sound but nonetheless carrying strong intrinsic associations with roundness and pointiness, respectively.