Obstinate and unruly; strongly opposed to something.
Not affected by great heat.
Difficult to treat.
Incapable of registering a reaction or stimulus.
A material or piece of material, such as a brick, that has a very high melting point.
Easy to deal with or manage
Capable of being easily led, taught, or managed.
Capable of being shaped; malleable.
Sufficiently operationalizable or useful to allow a mathematical calculation to proceed toward a solution.
Algorithmically solvable fast enough to be practically relevant, typically in polynomial time.