â¢ FUSION (noun) The noun FUSION has 7 senses: 1. an occurrence that involves the production of a union. 2. a nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy. 3. the state of being combined into one body. 4. the merging of adjacent sounds or syllables or words.
1 A new kind of online ad fraud â ad injection â is a growing threat for publishers and web users, ad fraud detection companies told the Wall Street Journal.  The practice goes like this: Fraudsters commandeer website visitors' browsers and fraudulently serve ads on publishers' websites.
ADH (antidiuretic hormone): A peptide molecule that is released by the pituitary gland at the base of the brain after being made nearby (in the hypothalamus). ADH has an antidiuretic action that prevents the production of dilute urine (and so is antidiuretic).