Definition of regnal
: of or relating to a king or his reign; specifically : calculated from a monarch's accession to the throne <in his eighth regnal year>
Origin and Etymology of regnal
Medieval Latin regnalis, from Latin regnum reign — more at reign
First Known Use: 1612
Seen and Heard
What made you want to look up regnal? Please tell us where you read or heard it (including the quote, if possible).