Characteristic
Part of speech: adjective
Definition: being a distinguishing feature of a person or thing
Part of speech: noun
Definition: a distinguishable feature of a person or thing the integer part of a logarithm the distinguishing features of a navigational light on a lighthouse etc by which it can be identified (colour, pattern of flashes etc)
Principle
Part of speech: noun
Definition: A fundamental assumption.A rule used to choose among solutions to a problem.Moral rule or aspect.A rule or law of nature, or the basic idea on how the laws of nature are applied.A fundamental essence, particularly one producing a given quality.A beginning.