English
fiducially
From fiducial + -ly.
Formed from fiducial + -ly
Proto-Indo-European *bʰeydʰ- ‘to trust’
…
Proto-Italic *feiðō ‘to trust’
Late Latin fīdō ‘to trust’
Late Latin fīdūcia ‘trust, reliance’
Late Latin fīdūciālis
English fiducial
Today it means
adv With confidence.
Language periods are conventional ranges, not dates for this word.
Etymograph / fiducially