(adjective)
belonging to or characteristic of an earlier period of time, especially the ancient times;
e.g. There is an increasing demand for antique furniture among buyers.
(adjective)
outdated or old-fashioned, of a style belonging to earlier times;
e.g. This is an antique sewing machine that must be operated manually.
(adjective)
relating to old objects from earlier times, either literally (as in selling such objects) or figuratively/humorously (as in ridiculing something for its wear or age);
e.g. I bought this vase at an antique store.
(verb)
to use artificial finishing techniques in order to make something appear as though it is an antique;
e.g. The craftsman uses this method to antique his furniture before selling it.
(verb)
in American usage, to go shopping for antiques or to search for some specific such object (often used as "antiquing");
e.g. While I was antiquing, I came across a beautiful gramophone.