a. [ L. indubitabilis: cf. F. indubitable. See In- not, and Dubitable. ] Not dubitable or doubtful; too evident to admit of doubt; unquestionable; evident; apparently certain; as, an indubitable conclusion. -- n. That which is indubitable.

Syn. -- Unquestionable; evident; incontrovertible; incontestable; undeniable; irrefragable. [ 1913 Webster ]

n. The state or quality of being indubitable. [ 1913 Webster ]