Word: kofun
Part of speech: Noun
Syllables: ko
fun
Definition: A megalithic tomb or tumulus in Japan, often with a distinctive keyhole-shaped mound.
Morphemes:
Affix: kofun
Language: en
PoS: Noun
Meaning: A megalithic tomb or tumulus in Japan, often with a distinctive keyhole-shaped mound.
Etymology Compounds: Affix: 古墳
Language: ja
Decoded: Gu Fen 
Meaning: ancient grave