Meaning of the word "on the up and up" in English

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

on the up and up

US /ɑːn ði ˌʌp ənd ˈʌp/
"on the up and up" picture
1.
Learn This Word at Lingoland