Implicature
Implicatures are inferences that enable interlocutor to go beyond what speakers say to what speakers actually mean. The inferences are not part of the truth conditions of propositions conveyed by utterances nor are they logical entailments.They are based on assumptions about speakers following the maxims of conversation.
If the question Is Jane a good cook? Elicits the response her mother`s a good cook, the questioner will probably infer, not that the interlocutor is maliciously changing the topic, but that he or she is saing indirectly that Jane is not a good cook. Such an inference is a conversational implicature. Some analysts distinguish generalixed conversational implicatures and particularized conversational implicatures. The former require no context, the latter need a particular context.
conversational implicatures are attached by convention to particular words.
⠀ The Cambridge dictionary of linguistics / Keith Brown and Jim Miller ISBN 978-0-521-76675-3