inflection of douter:
/ inflection of douter:

doubt

no doubt, most probably, most likely

in doubt; if in doubt; when in doubt / since X was in doubt, to be on the safe side, to be safe

(formal) Alternative form of sans doute: no doubt, undoubtedly, most certainly, most probably, most likely

undoubtedly (without any doubt)

(transitive) to question, to call into question, to cast doubt upon, to doubt, to challenge, to second guess

benefit of the doubt

to be a certainty, to be clear

undoubtably; beyond the shadow of a doubt