be, sit or stand astride, extend over, straddle
跨 centers on positioning oneself or something across a gap or boundary: straddling, sitting or standing astride, or extending over from one side to the other.
跨 combines 足 (foot/leg) with 夸, which likely contributes the sound and the idea of extending or spanning. The character suggests stepping or standing across something.
The left side is 足 (foot/leg), and the right side 夸 looks like a person with arms spread wide. Picture a person spreading their legs wide to straddle a gap: 跨 means to straddle or extend over.
For コ, imagine a person straddling a small cove: cove -> コ, and their legs extend across the water.
to step over; to step across; to stride over; to stride across; to cross
to straddle; to sit astride; to mount
bridge over a railroad (esp. a footbridge); overpass
one stride; single stride
step or stride (over something)
crotch; thigh; groin
straddle-beam type
across the tracks (of a bridge, etc.); over the tracks
overpass