[SonicPs]

"Sanction" is an interesting word, in that, depending on context, it can have diametrically opposing meanings. Words like this are called contronyms.
For example, the word "fast" can mean "moving quickly" as in "running fast", or it can mean "not moving" as in "stuck fast". To buckle can mean "to fasten" or "to bend then break". To weather can mean "to endure" or "to erode." This phenomenon is also called "enantionymy" or "antilogy".