Washington(CNN) "Nut job" seems to be one of President Donald Trump's favorite insults for his political foes.
The President -- who The New York Times reported Friday bragged to two Russian officials that firing "nut job" FBI Director James Comey eased "great pressure" on him in regard to the Russia probe -- has a history of slapping the label on people he disagrees with.
By definition, nut job means a "mentally unbalanced person," according to Merriam-Webster, which tweeted Friday lookups of the word spiked 173,750%.
"'Nutjob' is our number 2 lookup right now," the dictionary's Twitter account tweeted Friday, using one of the two spellings for the phrase.
"'Nutjob' is derived from the word 'nut' ("a crazy person") combined with the word 'job,'" Merriam-Webster wrote in a blog post on its website Friday. "Yes, that's really it."
In October 2015, Trump directed the term at "wacky Glenn Beck." Trump said the nationally syndicated radio host is a "real nut job" because he "always seems to be crying."
On the campaign trail, in February 2016, Trump criticized former presidential candidate Lindsey Graham, who was vocal about his disapproval for Trump.
"I saw him on television this morning, and I think he lost it. He said 'Donald Trump, he's' -- he couldn't even talk," Trump said during a campaign event in South Carolina, where Graham is a senator. "He was shaking. The hatred. They say, 'What do you think of Donald Trump? Well, waahhh.' He went crazy. The guy is a nut job."
He also called former Democratic presidential candidate Bernie Sanders a "nut job" while at a rally in San Jose in June 2016.
The Vermont senator laughed when asked about it by NBC New York.
Notably, Trump also said North Korean leader Kim Jong Un "could be a total nut job."
"I mean, you've got this madman playing around with the nukes, and it has got to end. He's certainly -- he could be a total nut job, frankly," Trump said on Fox News' "On The Record" in January 2016.
In May, however, he had a change of heart about the leader. Trump said he would be "honored" to meet Kim Jong Un "under the right circumstances" and called called him a "smart cookie."
POTUS has also used a similar term -- "basket case" -- to describe former Republican presidential candidate Jeb Bush.
"@JebBush was terrible on Face The Nation today," Trump tweeted in December 2015. "Being at 2% and falling seems to have totally affected his confidence. A basket case!"
Trump has publicly called Comey, whom he fired last week, "a showboat" and a "grandstander."