overhumble
/ˌoʊvərˈhʌmbəl/Definitions
1. adjective
having or showing an excessively modest or humble attitude; excessively modest in one’s own abilities or achievements.
“The overhumble student always downplayed his academic achievements.”
2. noun
a person who is excessively modest or humble.
“The overhumble colleague was reluctant to take credit for the team’s success.”