Denotation -

1. The literal or primary meaning of a word, in contrast to the feelings or ideas that the word suggests.
2. The action or process of indicating or referring to something by means of a word, symbol, etc

Connotation -

1. An idea or feeling that a word invokes for a person in addition to its literal or primary meaning.
2. The implication of such ideas or feelings.

Convention -

1. A way in which something is usually done, esp. within a particular area or activity.
2. Behavior that is considered acceptable or polite to most members of a society