Anything relating to meaning in language. All words we use have some meaning and those meanings often relate to each other. For example we know that apples, pears and bananas are all different, each word has its own meaning, but they are also all related because they are all fruits and things you can eat. Sentences also have meanings which can be more tan the added meanings of the words inside them. Think about figures of speech like ‘You’re driving me round the bend’. The meaning of the sentence is different from the meanings of the words inside it.