Elusive (adjective): hard to comprehend or define

“This is how you ground yourself in an elusive, unfamiliar city – on foot, walking it into focus in all its specificity and wonder.”

“Walk with Me” – David L Ulin

Initially when this word was first encountered, the initial thought was that it meant something that was hard to catch. However, upon looking up the word I found out that it can also mean something that is mental.