certainly

As a noun speculation

is the process of thinking or meditating on a subject.

As an adverb certainly is

in a way which is certain; with certainty.

As an adverb certainly

is in a way which is certain; with certainty.

As a noun assurance is

the act of assuring; a declaration tending to inspire full confidence; that which is designed to give confidence.

As a noun certitude

is (uncountable) sureness, certainty.

As an adverb certainly is

in a way which is certain; with certainty.

As adverbs the difference between completely and certainly

is that completely is in a complete manner; fully; totally; utterly while certainly is in a way which is certain; with certainty.

As adverbs the difference between certainly and very

is that certainly is in a way which is certain; with certainty while very is to a great extent or degree; extremely; exceedingly.

As an adjective very is

true, real, actual.

As adverbs the difference between certainly and successfully

is that certainly is in a way which is certain; with certainty while successfully is in a successful manner; with success; without failing.

As an adverb certainly

is in a way which is certain; with certainty.

As a noun community is

a group sharing a common understanding and often the same language, manners, tradition and law. See civilization.

As adverbs the difference between certainly and strongly

is that certainly is in a way which is certain; with certainty while strongly is in a strong or powerful manner.

As adverbs the difference between certainly and firstly

is that certainly is in a way which is certain; with certainty while firstly is (formal) in the first place; before anything else; first.

As adverbs the difference between certainly and apparently

is that certainly is in a way which is certain; with certainty while apparently is plainly; clearly; manifestly; evidently.