معنی کلمه climb up or down

go up

come up,

step gradually up /down

Their children used to climb up and pee into our yard.

(intransitive) to make a gradual ascent or increase. (transitive) to gradually ascend something.

We usually use climb with two prepositions, i.e. – 'up' and 'down'. They indicate the direction of climbing. For e.g. - Climb up a mountain and Climb down a mountain. In the sentence given above in the question – the direction of climbing is up