Definition from Wiktionary, the free dictionary
- calm and quiet; peaceful; tranquil
- a placid disposition
- a placid lake
1847, Charlotte Brontë, chapter 9, in Jane Eyre, HTML edition:
- April advanced to May: a bright serene May it was; days of blue sky, placid sunshine, and soft western or southern gales filled up its duration.
2014 October 21, Oliver Brown, “Oscar Pistorius jailed for five years – sport afforded no protection against his tragic fallibilities: Bladerunner's punishment for killing Reeva Steenkamp is but a frippery when set against the burden that her bereft parents, June and Barry, must carry [print version: No room for sentimentality in this tragedy, 13 September 2014, p. S22]”, in The Daily Telegraph (Sport):
calm and quiet; peaceful