The Collaborative International Dictionary
Janus-faced
Janus-faced \Ja"nus-faced`\, a. Double-faced; deceitful.
Janus-faced lock, one having duplicate faces so as to go
upon a right or a left hand door, the key entering on
either side indifferently.
--Knight.
Usage examples of "janus-faced".
Cognitive science is therefore Janus-faced, for it looks down both roads at once: One of its faces is turned toward nature and sees cognitive processes as behavior [standard Right-Hand approach].