A third usage (particularly that of the influential Lyons 1968, 1977) defines the term antonym as referring to only gradable opposites (the long : short type) while the other types are referred to with different terms. Therefore, as Crystal (2003) warns, the terms antonymy and antonym should be regarded with care. In this article, the usage of Lyons (1963, 1977) and Cruse (1986, 2004) will be followed where antonym is restricted to gradable opposites and opposite is used as the general term referring to any of the subtypes discussed below.
General discussion
Opposites are, interestingly, simultaneously different and similar in meaning. Typically, they differ in only one dimension of meaning, but are similar in most other respects, including similarity in grammar and positions of semantic abnormality. Additionally, not all words have an opposite. Some words are non-opposable. For example, animal or plant species have no binary opposites (other than possible gender opposites such as lion/lioness, etc.); the word platypus therefore has no word that stands in opposition to it (hence the unanswerability of What is the opposite of platypus?).
Other words are opposable but have an accidental gap in a given language's lexicon. For example, the word devout lacks a lexical opposite, but it is fairly easy to conceptualize a parameter of devoutness where devout lies at the positive pole with a missing member at the negative pole. Opposites of such words can nevertheless sometimes be formed with the prefixes un- or non-, with varying degrees of naturalness. For example, the word undevout appears in Webster's dictionary of 1828, while the pattern of non-person could conceivably be extended to non-platypus.
Opposites may be viewed as a special type of incompatibility.Words that are incompatible create the following type of entailment (where X is a given word and Y is a different word incompatible with word X):
- sentence A is X entails sentence A is not Y
An example of an incompatible pair of words is cat : dog:
- It's a cat entails It's not a dog
This incompatibility is also found in the opposite pairs fast : slow and stationary : moving, as can be seen below:
- It's fast entails It's not slow
- It's stationary entails It's not moving.
- Common opposites.
-    add – subtract addition - subtraction afraid - brave agree - disagree ahead - behind alive - dead alone - crowd alone - group ancient - modern Angel - Devil around - through arrive - leave awake - asleep bent - straight big - little blow - suck blunt - sharp boring - interesting boy - girl boy - man break - fix bride - groom bring - remove buy - sell calm - emotional careful - careless casual - formal centre - edge cheerful - grumpy cheers - jeers close to - away from cold - hot colour – colourless combined - separated come - go comedy - tragedy confident - worried correct - incorrect courteous - rude crazy - lucid create - destroy crooked - straight curly - straight damage - repair day - night drunk - sober dry - wet East - West easy - hard empty - full enlarge - reduce expand - contract fat – skinny/thin/slim first - last float - sink front - back frozen - melted giant - midget girl - woman give - take good - bad Grandma - Grandad grow - shrink guys & gals (slang) hairy - bald happy - sad hard - soft head - feet heads - tails Heaven - Hell help - hinder hero - villain hide - seek high - low his - her hit - miss hot - cold huge - tiny ill - well in - out in front - in back insane - sane into - out of King - Queen Ladies - Gentlemen large - small laugh - cry lead - follow left - right life - death light - dark lit - unlit long - short lots - little bit love - hate make - ruin man - woman many - few maximise - minimise me - you Men - Women Mum - Dad more - less most - least Mother - Father moving - still multiplication - division multiply - divide naked - clothed near - far neat - messy new - old normal - strange North - South off - on open - close open - shut order – chaos/mayhem outside - inside over - under pass - fail plain - fancy plump - lean plus - minus polite - impolite positive - negative pretty - ugly proud - disappointed push - pull quiet - loud raw - cooked real - imaginary real - pretend rich - poor right - wrong same - different scared - brave send - receive shallow - deep sick - healthy silent - noisy simple - complicated simple - difficult Sister - Brother slow - fast smile - frown some - none son - daughter Spring - Fall stand - sit stand up - sit down stiff - limp stingy - generous stop - go succeed - fail success - failure sun - moon sweet - sour take off - land tall - short throw - catch tied - untied to - from together - apart top - bottom towards - away from undressed - dressed united - divided up - down us - them walk - run war - peace whisper - shout white - black wide awake - sleepy wild - tame win - lose work - play wrap - unwrap write - erase yes - no young - old 
- Examples of opposites.  - Book of Opposites - A silk-screened book on opposites, using collaged portraits that are almost the same, but conveying two different meanings.    
