What is the meaning of Sound_symbolism?

Phonetic symbolism.

The phenomenon by which some speech sounds are associated with the meanings they convey, either intrinsically or by a recurring phono-semantic association, or an instance thereof; an ideophone.

1. speech sound that is neither arbitrary with respect to meaning nor an onomatopoeia that imitates a real sound
2. the property of such a sound or sequence of sounds

speech sound that is neither arbitrary with respect to meaning nor an onomatopoeia that imitates a real sound

the property of such a sound or sequence of sounds

Source: wiktionary.org