icon has 3 distinct synonyms spread across 2 of its 3 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
(computer science) a graphic symbol (usually a simple picture) that denotes a program or a command or a data file or a concept in a graphical user interface
a visual representation (of an object or scene or person or abstraction) produced on a surface
“they showed us the pictures of their wedding”
Synonyms, antonyms and the broader and narrower relations for icon come from Princeton University’s WordNet. Full sources and licences.