ˈnēpə(r), ˈnāp- noun
( -s )
Etymology: after John Neper (Napier) died 1617 Scottish mathematician who invented logarithms
: a unit on a natural logarithmic scale for expressing the relationship between two amounts of power (as electric power or acoustic power) equal to one half the natural logarithm of the ratio of the two powers compared : 8.686 decibels