The word "Cha" is derived from the Chinese character for tea.
It is pronounced as either "t'e" or "ch'a."
Derivatives of one or both
of these pronunciations appear
in almost every language
 for the beverage known as Tea.
In the ancient classic Shi Jing –
The Book of Songs,
tea was called ‘tu’ -

and in the ancient classic Er Ya
that was written and complied
 in the early Han dynasty
tea was called ‘jia’ -
Jia’ means bitter and ‘tu’
means small plant. Guo Pu  (276-324AD)
 also known as Jingchun (
 was a Jin dynasty scholar
born in Yun Cheng, ShanXi
was a noted natural historian
 and also a versatile and prolific
 writer, who annotated the word ‘tu’.
It was during the Han
 dynasty (206 BCE–220 CE) that
the word ‘tu’ began to be
pronounced ‘cha’.
In the Fujian dialect  the word ‘te’
developed to ‘tu’ then later tea
in English and later the word ‘jia’
became ‘cha’ and ‘chai’ in
Russia and India.
The Classics of Tea – Lu Yu’s Cha Ching
 (760 AD) is where the first
use of the word ‘cha’ is found.