The word ‘ginseng’ refers to plants from the family Araliaceae or to drugs originating from them. It is phonetically derived from the Chinese word 
("rén" = human) and 
("shēn").
The Chinese meaning
The character is a simplified pictograph of a walking human figure.
The meanings of the sign are distinguished by their pronunciation, but they are generally related to its function of the ancient numeral three (“sān”, today 
) and curiously enough, also to meanings like “participate”, “consult” and “counselor”. It is a similar situation as in Indo-European languages, where for example the word “critic” in its meaning of judge, consultant is derived through Greek "krités“ from "tritos", as if impartial person, who decides the dispute of two parties.
Today, the sign standing alone is only used to the Chinese constellation of Orion’s belt, consisting of three bright stars. The phoneme “shēn” combined with other characters is connected to meanings like spirit, breath, sigh, aristocrat, identity, life, body and the plant Asarum sieboldii. If we change the first tone in „shēn" to the second "shén", we get a phoneme, which written by the character 
means god, natural spirit, supernatural, genius.
It is obvious that ginseng is a root, so this fact is not etymologically emphasized – the initial ‘sh’ in ‘shēn’ can be changed to ‘g’ to get the syllable ‘gēn’, which normally means ‘root’ (written with the sign 
). The written and phonetic form of the word ‘řén-šēn’ thus, as is common in Chinese, evoke several complementary interpretations – from the humble ‘man’s root’, through ‘man’s advisor’ to more pompous ‘power of Earth in the form of a human’, if desired.
But one should not be in too much awe over this grandiloquent etymology. Exaggeration is a regular sight in Chinese, such as that food named ‘three treasures’, which is actually duck, chicken and pork meat wiith rice and cabbage.
(Used resources: zhongwen.com, Chinese Character Dictionary; the essay about phonetic relationships should be considered my own artistic creation.)