tranquilize, ancient peace-preservation centers
鎮 centers on pressing down to bring calm or stability: tranquilizing agitation, suppressing unrest, or holding a place secure. The historical reference to ancient peace-preservation centers is a specific institutional application of that same idea of enforced calm.
鎮 combines 金 (metal) with 真, which likely contributes the sound and the idea of pressing or weighting down. The character originally referred to using a metal weight to press down and stabilize, extending to the idea of calming or suppressing.
Metal (金) is heavy and can press things down. The right side 真 looks like a weight being pressed onto a surface. Together, 鎮 is like using a metal weight to hold something still and calm.
For チン, imagine a heavy metal weight pressing down with a resonant 'chin' sound as it settles everything into calm: chin -> チン.
local Shinto deity; tutelary god
suppression (of a riot, revolt, etc.); repression; putting down; quelling
pain relief; killing pain
enshrinement (of a deity); residing (in a shrine or sacred place)
calming down; settling down; quieting down; quietening down; subsiding; pacification; appeasement
leader; authority; mainstay
extinguishing; dying out (of a fire); putting out
a weight
requiem
repose of a soul
paperweight
ceremony for purifying a building site (before building commences); ground-breaking ceremony
guarding; protecting
to quell; to quiet
Ana'ichi (script)
town (in China)
bricking (e.g. of a smartphone)
riot control
the three Wuhan Cities
jiedushi (regional military governor in ancient China)