placid
PLAS-idadjMeaning calm and peaceful; not easily stirred up
Memory hook a PLACE to SIT: still water. Grandpa’s favorite place to sit is the river at sunrise, where not a ripple moves and even the duck dozes; it is placid.
At dawn the placid lake held the mountains like a mirror.
In context The old mare was placid, standing quietly through thunder and fireworks, while the young colt bolted at every bang.
Similar calm, tranquil, serene, peaceful
Opposite stormy, agitated, excitable, turbulent
From Latin placidus, “gentle, calm,” from placere (to please).