What is terrorism?

Yet again, the nation is engaged in a debate whether our most recent on-soil tragedy -- the Las Vegas shooting -- should be deemed as "terrorism." Most congress members are reluctant to use the word, as is law enforcement, claiming that they do not yet know the motive behind the shooter's actions. The Washington Post wrote an article around this debate, and opened the article in this manner:

For the third time in four months, a tragedy on U.S. soil is dominating the country's attention. And for the third time in four months, we're about to have a debate about whether to label such an act — perpetrated by a man with no known ties to Muslim extremism — as “terrorism.”

I find the above statement troubling. The Washington Post was quick to label terrorism as an act carried about by Muslim extremists... when in reality, the definition of terrorism simply defines a violent act with the motive to coerce a government or its citizens. While many terrorist attacks in recent times have been carried out by Muslim extremists, is it an ethical concern that The Washington Post jumped to this false definition of the term in the first paragraph of their article?

https://www.washingtonpost.com/news/the-fix/wp/2017/10/02/terrorism-or-not-las-vegas-reignites-a-real-and-really-important-debate/?utm_term=.676b8842a79f