Words that also mean the opposite of themselves

In yesterday’s post about Patrick Henry College’s national championship in moot court, tODD commented that “the word ‘moot’ is used rather bizarrely in common parlance. I know that etymologically speaking, it means ‘meeting’ (Entmoot, anyone?). But it is frequently used to mean ‘not worth debating,’ in near opposition to its primary definition of ‘debatable.’

Carl Vehse came back with this: “tODD has just pointed out one of the English words that is an auto-antonym (AKA antagonym, contranym, Janus word, enantiodrome, self-antonym, oxymoronym).” He then posted a link to a list “>of those words in English that have two meanings that completely contradict each other. Here are just a few:

apology 

(1) an admission of error accompanied by a plea for forgiveness (2) a formal defense or justification (as in Plato’s Apology), also referred to as an apologia

before 

(1) in advance of (“the future is before us”) (2) at an earlier time, previously (“our forefathers came before us”)[7]

cleave 

This is a homophone, where two words, spelled and pronounced alike, have different origins. (1) “To adhere firmly”, from Old English clifian. (2) to split (as with a cleaver), from Old English cleofan ^[10]

critical 

Can mean “vital to success” (a critical component), or “disparaging” (a critical comment).^[9]

custom 

As a noun, this means “conventional behavior”; but as an adjective, it means “specially designed”.

sanction 

“To permit” or “to restrict” (as in “economic sanctions.”)^[9

seed 

To add seeds, is in seeding a field, or to remove seeds, as in seeding a fruit.^[9]

strike 

Normally meaning “to hit”, in baseball it means “to miss”, and an extension of this usage has led to the meaning “to make a mistake”. Further adding to the contradiction, in bowling it refers to the best possible play. Another contradiction results with the phrase strike out: the baseball lineage leads to the meaning “to run out of hope”; but the original lineage also leads to the meaning “to start pursuing a desire”

suspicious 

Can mean that a person is acting in a way that suggests wrong-doing, i.e. “He seems very suspicious.” or can mean that the person in question suspects wrong doing in others, i.e. “He was suspicious of her motives.”