The word contronym (Also the synonym antagonym) is used to refer to words that by some freak of language evolution, are their own antonyms. Both contronym and antagonym are relatively recent neologisms.
Contronyms are special cases of homographs (two words with the same spellings).
Anabasis | Military advance |
Military retreat |
Aught | All |
Nothing |
Bolt | Secure |
Run away |
Buckle | Fasten |
|
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’) |
Off | 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) |