1880, B. Stewart and P. G. Tait, The Unseen Universe, Macmillan (London), p. xiii:There are those who have doubtless faith in revelation.
1927, Edgar_Rice_Burroughs, The Outlaw of Torn, ch. 7:It is doubtless that the old reprobate who sued for his daughter's hand heard some unsavory truths from the man.
(obsolete) Free from fear or suspicion.
ShakespearePretty child, sleep doubtless and secure.
1893, Ambrose_Bierce, "The Realm Of The Unreal":I cannot remember that I spoke a word, though doubtless I did.
1900, L. Frank Baum, The Wonderful Wizard of Oz:The men, Dorothy thought, were about as old as Uncle Henry, for two of them had beards. But the little woman was doubtless much older. Her face was covered with wrinkles, her hair was nearly white, and she walked rather stiffly.
