Different names for each of the fingers
Thumb: 拇(mŭ)指(zhĭ) or 大拇指 or 大拇哥.
The first two words are common while the last one is less common. You would hear it more in oral speaking, in some regions(I heard of it from one of my relatives in HeBei province).

Watch the shape of &quot;拇&quot;. The left part refers to &quot;hand&quot;, and the right part is &quot;母“， meaning &quot;mother&quot;. I think it gets this name because of the importance of the thumb. I consult it in the dictionary of 《康熙字典》. It cites &quot;【說文】將指也。&quot; I believe &quot;將指&quot; is an analogy that a thumb is like a general among fingers :)

Index Finger:食指(shí zhĭ)

I think we call it because we would dip this finger to the food(soup, etc) to taste the flavour(食 means to eat). There is a famous story from 《左传》 related the index finger and we coin a word &quot;染指&quot; from it(here, 染 means &quot;to dip&quot;). I won't tell you the story here, because it's a little bit long and complicated, sorry. You can search an idiom we get from it &quot;食指大动&quot; to find more info about this story.

Middle Finger: 中指(zhōng  zhĭ).  &quot;中&quot; means &quot;middle&quot;
Ring Finger: 无名指(wú míng zhĭ). Interesting, &quot;无名&quot; means &quot;without a name, anonymous&quot;
Pinky Finger:小指(xiăo zhĭ) or  小拇指(xiăo mŭ zhĭ). &quot;小&quot; means &quot;little, small&quot;