Meaning of the word "mount up" in English

What does "mount up" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

mount up

US /ˈmaʊnt ʌp/
UK /ˈmaʊnt ʌp/

Phrasal Verb

to increase gradually in amount or number

Example:
The costs of the project began to mount up rapidly.
The evidence against him continued to mount up.