Chinese

		up; on; on top up; on; on top; upon; first; previous or last; upper; higher; above; previous; to climb; to go into; to go up	to know; to be aware	astronomy		under; second; next under; second; next; lower; below; underneath; down(wards); to decline; to go down; latter	to know; to be aware	geography
simp. and trad. (上知天文，下知地理)		上	知	天文	，	下	知	地理
Literally: “know the astronomy above, and know the geography below”.

Idiom

上知天文，下知地理

1. describes someone who is very learned; a polymath