An example of indubitably is an attorney arguing an undoubtedly clear case for their client, indubitably arguing.
- In a manner that leaves no possibility of doubt; undoubtedly.
Currently particularly used as a humorous interjection, particularly in American English, and seen as somewhat affected, if not outright campy. Compare this use by comedy cartoon Alex Hopper (US, 1947-65).
indubitable + -ly