Entry: intractable (adj.)
In context: "The D.E.A. had lost four field researchers and a consultant before they'd bowed to the intractable problems involved in trying to have somebody view the confiscated Tempe cartridge and articulate the thing's lethal charms."
Definition: Of things: Not to be manipulated, wrought, or brought into any desired condition; not easily treated or dealt with; resisting treatment or effort.
Of persons and animals: Not to be guided; not manageable or docile; uncontrollable; refractory, stubborn.
Other: Wonderful word!
A bit of a strange usage, this appears not under Of persons and animals, but as part of Of things, though I guess a tooth is hardly an animal:
1607 E. Topsell Hist. Fovre-footed Beastes 193 The teeth of those Elephants..are so smooth and harde, as they seeme intractable.
SNOOT score: 3
Source: Oxford English Dictionary