People who think they are helping but are actually counter productive to the task at hand. Example: Granddad, I know an 8th grade education was good enough for you but telling your grandson to stick it out til his is 18 and then do what you want on schooling is not supporting how we raise our kids!
UNDERMINERS
Meaning of UNDERMINERS in English
Slang English vocab. Английский сленговый словарь. 2012