Refers to the act of going up, an upward slope, or a climbing route. 登り is common for physical climbing.
The ascent of this mountain is steep.
I got out of breath on the climb up the stairs.
up-train; upbound (toward Tokyo)
Only when written 上り
Used for trains or travel heading toward the starting point of a route, especially toward Tokyo. Sense 3 is the adjectival use.
See also: 上り列車
The up-train is bound for Tokyo.
I take an upbound Shinkansen.
upstream; uphill
Only when written 上り
Used as a noun or prefix for upward direction in geographical contexts, such as upstream or uphill. Often appears in compounds like 上り勾配 (uphill slope).
See also: 上り勾配 (のぼりこうばい)
Check the upstream direction of the river.
A road with a continuous uphill slope.
I'm heading to Tokyo on the up-bound train.
In the morning, the up-bound trains are crowded.
上り refers only to the upward part of the movement, whereas 上り下り covers both the ascent and the descent together.
up line; inbound line
going up and down; ascent and descent