What is syllable to thistle?

There is no direct relationship or connection between the words "syllable" and "thistle." They are completely different words with separate meanings.

* Syllable: A unit of pronunciation consisting of a single vowel sound, with or without surrounding consonants.

* Thistle: A prickly plant with purple flowers.

It seems like you might be looking for a relationship or connection that doesn't exist. Can you clarify your question or provide more context?