I was looking up the word زحف (z-H-f) in the dictionary, for a class with Shaykh Faisal Matadar, and noticed something interesting.

A lot of the words that are formed with ز as the first root letter have to do with movement of some kind (usually with force, pressure):

z – b – d – to churn
z – b – q – to tear out
z – j – j – to hurl
z – j – r – to drive back
z – j – l – to let go, release
z – j – w – to drive, to urge on, to force, to cram
z – H – z – H – to move, to tear, to rip
z – H – f – to crawl, creep, to advance troops
z – H – l – to move away, to withdraw
z – H – l – q – to slip
z – H – m – to push, to shove, to jostle
z – kh – r – to swell, to rise
z – kh – m – to thrust back
z – r – b – to flow (water)
z – r – d – to choke, to swallow
z – r – 3 – to sow, to scatter
z – r – q – to drop excrement
z – 3 – j – to pester, to disquiet, to alarm
z – 3 – z – 3 – to shake violently
z – 3 – f – to kill instantly
z – l – z – l – to shake violently (earthquake)

…and this is not exhaustive by any means (3 is the ‘ayn letter).

If you think of tajwīd, the makhraj (point of articulation) of ز is the “tip of the tongue.” To make the sound the teeth need to be PRESSED together, so that the air passage makes a buzzing noise (indicating movement of sound!).

SubhanaAllah.