(後 "spatially behind") to depart from; to leave / (後 "temporally later") to put off something, to be dealt with later

(idiomatic) A piece of cake; an extremely simple thing, something trivial, a cinch, easy as pie.

朝飯前: A piece of cake; an extremely simple thing.

(telephony) a common Japanese telephone greeting: hello; used when answering the telephone / used to confirm that the person being addressed is listening, or to confirm if anyone is listening

put away

seismology

a large earthquake; typically has a magnitude 7 or greater

a large earthquake; typically has a magnitude 7 or greater

a seismologist

Kyūjitai form of 地震学: seismology