1pro 
/ˈproʊ/ noun
plural pros /ˈproʊ/ noun [count] : an argument for something : a reason to do something — usually plural ▪ Make a list of the pros and a list of the cons and then compare them. ▪ The pros outweigh the cons. [=there are more advantages than disadvantages] ▪ Congress weighed the pros and cons of the new tax plan. [=the arguments for and against the new tax plan] 2 : a person who supports or is in favor of something
▪ When the new law was proposed, we began hearing arguments from both the pros and the cons. [=from the people who supported it and the people who opposed it]
▪ When the new law was proposed, we began hearing arguments from both the pros and the cons. [=from the people who supported it and the people who opposed it]
— compare 3pro
