hard to manage; not tractable; difficult to manage or mold
The intractable problem resisted all attempts at solution.
Vocabulary like intractable appears on the Digital SAT in Words-in-Context questions, where you choose the word that fits a passage's meaning and tone. You can also drill this word with vocabulary flashcards.
an unwelcome intruder
middle; lying between two extremes in time or space or state
endless; tiresomely long; seemingly without end
irregular; stopping and starting at irregular intervals
explain; make sense of; assign a meaning to
period; a definite length of time marked off by two instants
interrupt; get involved, so as to alter an action, or through force or threat of force
frighten; make timid or fearful