say it: TRANG-kwuhl
tranquil is an adjective meaning "(of a body of water) free from disturbance by heavy waves". It carries 2 recorded senses.
(of a body of water) free from disturbance by heavy waves
“a ribbon of sand between the angry sea and the placid bay”
“the quiet waters of a lagoon”
“a lake of tranquil blue water reflecting a tranquil blue sky”
“a smooth channel crossing”
“scarcely a ripple on the still water”
“unruffled water”
not agitated; without losing self-possession
“spoke in a calm voice”
“remained calm throughout the uproar”
“he remained serene in the midst of turbulence”
“a serene expression on her face”
“she became more tranquil”
“tranquil life in the country”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for tranquil come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.