LT5903 Chap.6 Lexical Meaning and Semantic Relations
Lexical Meaning and Semantic Relations
Meaning through relations and truth
Semantics separates sense from reference and uses set relations to organise lexical meaning. Hyponymy, synonymy and several types of antonymy behave differently. Compositional semantics combines expression meanings with syntactic structure, while idioms resist ordinary composition. Adjectives can be intersective, subsective, non-intersective or anti-intersective.
At sentence level, propositions have truth conditions, and entailment, mutual entailment and incompatibility are tested across possible situations rather than by whether a claim happens to be true.
Separate sense from reference
Reference connects an expression to an entity or set in a situation, while sense concerns the expression's conventional meaning and relations within the language.
Two expressions may share a referent yet present it differently, and an expression can have an intelligible sense even when no actual referent exists. Use this contrast to avoid treating co-reference as synonymy.
When analysing a case, specify whether the evidence concerns the object selected, the descriptive content or a relation between linguistic expressions.
Test lexical relations as set relations
A hyponym denotes a subset of its hypernym: every robin is a bird, but not every bird is a robin. Synonymy requires mutual substitution or highly similar sense, though register and context often prevent absolute identity.
Complementary antonyms divide a domain into two alternatives, gradable antonyms allow intermediate values and reversives describe opposed changes. Write the relevant entailment in both directions.
This exposes whether the relation is inclusion, equivalence, incompatibility or merely association.
Compose meaning through structure
The meaning of a complex expression normally depends on the meanings of its parts and the way syntax combines them. The same words can therefore yield different interpretations under different structures.
Idioms are important because their established meaning is not fully predicted by ordinary composition, although their internal grammar may still show restrictions. Do not use compositionality to ignore ambiguity.
First fix a structure and word sense, then state how the pieces contribute to the result.
Classify adjective-noun combinations
An intersective adjective places the referent in both the adjective set and noun set. A subsective adjective guarantees membership in the noun set but may not define an independent adjective set.
A non-intersective adjective does not license the inference that the referent belongs to the noun set, and an anti-intersective adjective supports the opposite. Test each inference explicitly rather than relying on intuition about the adjective.
Context can influence which reading is active, so state the interpretation being assessed.
Use countermodels for entailment
To test whether proposition A entails proposition B, try to construct a coherent situation where A is true and B false. If no such situation is possible because of meaning, the entailment holds. Mutual entailment requires the test in both directions.
Incompatibility means the propositions cannot both be true, which differs from one entailing the negation only in carefully specified domains. Actual truth is irrelevant: a false premise can still stand in a semantic relation. Show the attempted countermodel so the reasoning is inspectable.
What this chapter covers
- 01
Sense and reference
- 02
Hyponymy and synonymy
- 03
Types of antonymy
- 04
Adjective composition
- 05
Truth conditions and entailment
Worked example · free
Search for a countermodel
- 2State both truth conditions.
- 3Construct a possible counter-situation.
- 2Give the verdict.
Key terms
- Sense
- The concept associated with an expression.
- Reference
- The entity or set an expression picks out.
- Hyponym
- A term whose extension is contained within another term's extension.
- Truth Condition
- What must hold for a proposition to be true.
- Entailment
- Guaranteed truth of one proposition given another.
Lexical Meaning and Semantic Relations FAQ
Can an expression have sense without reference?
Yes. A conventional concept may be understood even when no actual entity satisfies it. This is why reference cannot exhaust meaning and why two expressions can share a referent while presenting that entity through different senses.
How do intersective and anti-intersective adjectives differ?
An intersective phrase denotes the overlap of the adjective and noun sets. An anti-intersective adjective blocks membership in the noun set, as with an imitation object. Draw the sets to make the difference explicit.
Does a true conclusion prove entailment?
No. Entailment asks whether the conclusion must be true whenever the premise is true. A conclusion can happen to be true for unrelated reasons. Search for a possible countermodel rather than checking actual truth values.
Exam move
Draw lexical relations as sets or hierarchies, then convert sentence claims into truth conditions. For every proposed entailment, try to construct one countermodel before accepting it. Run the test in both directions to distinguish inclusion from equivalence, and state the domain when classifying antonyms. For adjective problems, list the noun-set inference explicitly rather than deciding from how natural the phrase sounds.
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