say it: SEEZ-luh-slee
ceaselessly is an adverb meaning "with unflagging resolve". It carries one recorded sense.
with unflagging resolve
“dance inspires him ceaselessly to strive higher and higher toward the shining pinnacle of perfection that is the goal of every artiste”
Definitions, synonyms and semantic relations for ceaselessly 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.