balker
/ˈbɔːlkər/Definitions
1. noun
A person who habitually or obstinately objects or complains; a carper or fault-finder.
“The balker of the project had to be convinced to change the design before it could move forward.”
2. verb
To object or complain habitually or obstinately; to carp or find fault.
“The engineer’s habit of balking every suggestion made by his team members was causing tension.”