Sturgeon's Law

Sanction: To sanction something is to approve or endorse it. To enact sanctions is to penalize or punish.

Prevail (not quite 180 degree opposites, but maybe 130 degrees apart or something): can mean to plea for help; or can mean to emerge victorious.

Table (used as a verb): in parliamentary procedure, in British usage, to table a motion is to bring it up for formal discussion; in U.S. usage, to table a motion is to postpone discussion until later.

Peculiar: can mean either unusual commonplace. Penguins are peculiar to (commonplace in) Antarctica. If you see penguins roaming around the Mojave desert, however, that's peculiar.
 

Under "prevail," I should have said "plead" for help...
 

Here's a crappy poem that I published several years ago and that was inspired, in part, by the subject of your post:


Redemption


I. re deem (ridí:m)||(theol.) to free from the bondage of sin


in a room
emptied of light he finds

love being made
despite his being

in darkness his body is
redeemed



II. re deem (ridí:m)||(v.t.) to save from being a total failure


despite love of light
she finds a darkness

emptied in her body
being is being

made redeemed
in her room

---
It doesn't work well, I know. But it took me a very long time to write, so I like to share it whenever I can. lol.
 

Hi Steven: I think these kinds of words are called "contronyms." Here is a list from one of my favorite internet sites:

aught - all, nothing
bolt - secure, run away
by - multiplication (e.g., a three by five matrix), division (e.g., dividing eight by four)
chuffed - pleased, annoyed
cleave - separate, adhere
clip - fasten, detach
consult - ask for advice, give advice
copemate - partner, antagonist
custom - usual, special
deceptively smart - smarter than one appears, dumber than one appears
dike - wall, ditch
discursive - proceeding coherently from topic to topic, moving aimlessly from topic to topic
dollop - a large amount, a small amount
dust - add fine particles, remove fine particles
enjoin - prescribe, prohibit
fast - quick, unmoving
first degree - most severe (e.g., murder), least severe (e.g., burn)
fix - restore, castrate
flog - criticize harshly, promote aggressively
garnish - enhance (e.g., food), curtail (e.g., wages)
give out - produce, stop production
grade - incline, level
handicap - advantage, disadvantage
help - assist, prevent (e.g., "I can't help it if...")
left - remaining, departed from
liege - sovereign lord, loyal subject
mean - average, excellent (e.g., "plays a mean game")
off - off, on (e.g., "the alarm went off")
out - visible (e.g., stars), invisible (e.g., lights)
out of - outside, inside (e.g., "work out of one's home")
oversight - error, care
put out - extinguish, generate (e.g., something putting out light)
quiddity - essence, trifling point
quite - rather, completely
rent - buy use of, sell use of
rinky-dink - insignificant, one who frequents RinkWorks
sanction - approve, boycott
sanguine - hopeful, murderous (obsolete synonym for "sanguinary")
screen - show, hide
seed - add seeds (e.g., "to seed a field"), remove seeds (e.g., "to seed a tomato")
strike - hit, miss (in baseball)
table - propose (in the United Kingdom), set aside (in the United States)
transparent - invisible, obvious
unbending - rigid, relaxing
variety - one type (e.g., "this variety"), many types (e.g., "a variety")
wear - endure through use, decay through use
weather - withstand, wear away
wind up - end, start up (e.g., a watch)
with - alongside, against

Probably more than you wanted to know. But what the heck! Hope it is useful to you. ~grin~
 

Not so much opposite in meaning but opposite in terms of subject/object: comprise. Ex. The board comprises five people. Five people comprise the board.
 

Peter, I knew this would be your sort of thing. :-)