Difficult to treat (of a medical condition).
Difficult to deal with, solve, or manage.
(of a mathematical problem) Not able to be solved.
Not tractable; not able to be managed, controlled, governed or directed.
Stubborn; obstinate.
Skill or ability of perceiving spoken language.
Action of the verb listening
An educational exercise involving listening
Of an action that is performed with caution and attention to sounds.
Of something that is used in order to hear or to improve the ability to hear.
Of something or someone that listens.