The word 'resinous' is an adjective and the noun from which it is formed is resin. Resin conveys the idea of a sticky substance that some trees produce. The substance is used in making of various industrial products and the main area where you can use it is in the making of varnish. It has its use also in the manufacturing of medicine. The following sentence can help you in understanding the word quite well as it is used in the adjective form: When you go near the pine tree you can feel the resinous smell of it.
The substance can be found naturally as well as it can be made artificially and in the artificial form it is usually used in the making of plastics.
The substance can be found naturally as well as it can be made artificially and in the artificial form it is usually used in the making of plastics.