Definition of mounting adjective from the Oxford Advanced Learner's Dictionary

mounting

adjective
ˈmaʊntɪŋ
 
; ˈmaʊntɪŋ
 
 
[only before noun] increasing, often in a manner that causes or expresses anxiety
Synonym
growing
mounting excitement/concern/tensionThere is mounting evidence of serious effects on people's health.In the face of mounting pressure, the president decided to act.