an act of scaling by the use of ladders (especially the walls of a fortification)
"The soldiers successfully managed to escalade the fortress wall during the surprise attack, relying entirely on their portable wooden ladders."
An act of scaling walls or fortifications
"The climbers began their ascent by scrambling up the sheer rock face to bypass the fortress gates."
To scale the walls of a fortification.
"The desperate climbers managed to escalade the crumbling stone walls before the guards could seal the gates."