Longman Dictionary of Contemporary English - substance

~ n 1 »MATERIAL« a type of solid or liquid that has particular characteristics  (a sticky substance | radioactive substances | Heroin is an illegal substance.) 2 »IDEAS« formal the most important ideas contained in an argument or piece of writing; essence (1)  (the substance of)  (The substance of his argument was that too many people live below the poverty line. | in substance)  (What she said in substance was that the mayor must resign.) 3 »IMPORTANCE« formal importance, especially because of dealing with things that are necessary; significance  (It was an entertaining speech, but without much substance. (=without many important or serious ideas) | matters/issues of substance)  (Instead of debating points of procedure, we should be discussing matters of substance.) 4 »TRUTH« (uncountable usually in questions and negatives) formal basic facts that are true  (There is no substance to the rumour that the princess is pregnant.) without substance (=untrue) 5 substance abuse technical the habit of taking too many drugs so that you are harmed by them 6 a man/woman of substance literary a rich man or woman 7 »REAL« something that really exists that you can feel  (phantoms without substance)