dem·on·stra·tion 
/ˌdɛmənˈstreɪʃən/ noun
plural dem·on·stra·tions /ˌdɛmənˈstreɪʃən/ noun 1 : an act of showing someone how something is used or done [count] ▪ I went to a sculpture demonstration last weekend. ▪ One of the instructors gave/did a demonstration of how to prune a tree. ▪ Would you mind giving us a demonstration so that we can see how the machine works? [noncount] ▪ He brought along a copy of the software for demonstration. — sometimes used before another noun ▪ We saw a demonstration [=demo] version of the new software. 2 : an event in which people gather together in order to show that they support or oppose something or someone [count] ▪ Students took part in several nonviolent/peaceful demonstrations against the government. ▪ demonstrations against the war = antiwar demonstrations ▪ demonstrations for women's rights [noncount] ▪ Protesters marched in demonstration. 3 : an act of showing or proving something [count] ▪ The latest tests are a clear demonstration that the vaccine works. — often + of ▪ a demonstration of their power/loyalty/skill ▪ a demonstration of grief/bravery ▪ They brought some bread to share as a demonstration [=token] of goodwill. [noncount] ▪ Many people sent cards and flowers in demonstration of their sympathy.
— dem·on·stra·tion·al /ˌdɛmənˈstreɪʃənl̟/ adjective
▪ a demonstrational video
/ˌdɛmənˈstreɪʃənl̟/ adjective ▪ a demonstrational video
