What is the synonym of mounting?

Answer 1

Depending upon the context, "escalating" or "increasing" may work.

For example, "Tension is mounting between X and Y."

"Tension is escalating between X and Y.

This does not work in the sentence "I spent the day mounting pictures." I suggest "hanging" works in that context.

In the sentence, "Bob fell while mounting his bicycle," "hanging" clearly doesn't work. In that case, "getting on" works well as a synonym.