Sen. Ted CruzRafael (Ted) Edward Cruz32 male senators back Senate women's calls to change harassment rules Senate confirms Trump’s pick to lead NASA DOJ denies reports judicial nominee once called illegal immigrants 'maggots' MORE (R-Texas) on Tuesday promised to speak until he can't stand up anymore, which launched an immediate debate on whether his speech is a filibuster or just a really long speech.

Cruz's defenders said the speech about the need to defund ObamaCare is a filibuster. But Democrats repeated throughout the day that it's just a really long speech.

So which is it? It depends who you ask — parliamentary experts say there is no precise definition of "filibuster."

Many see a filibuster as talking on the Senate floor for an extended period of time in order to prevent action on measure. If that's the case, Cruz's speech today seems to fall short, because regardless of his remarks, the Senate will vote by Wednesday on whether to end debate on a motion to proceed to the House-passed continuing resolution.

In other words, he can talk and talk, but that vote will happen on Wednesday at the latest because Senate Democrats filed cloture on the motion to proceed. Under Senate rules, filing for cloture sets up a firm vote after two days.

Senate Majority Leader Harry ReidHarry Mason ReidDems walk tightrope on Pompeo nomination The Memo: Teens rankle the right with gun activism Dems to party: Go on offense with Trump’s alleged affairs MORE (D-Nev.) made it clear today that this is his preferred definition of "filibuster."

"I want to disabuse everyone," Reid said this morning. "There will be no filibuster today. Filibusters stop people from voting, and we are going to vote tomorrow."

But some say the term "filibuster" can be used to describe any dilatory tactic that delays the legislative process. If that's the case, Cruz's comments can be seen as a filibuster, because his opposition to moving ahead with the bill is preventing senators from reaching a unanimous consent agreement to vote earlier on ending debate on the motion to proceed.

The Senate's own website seems to agree that any delaying tactic is a filibuster. The website defines the word as an "informal term for any attempt to block or delay Senate action on a bill or other matter by debating it at length, by offering numerous procedural motions, or by any other delaying or obstructive actions."

So while Cruz didn't start his remarks by saying he is filibustering the continuing resolution, experts say he can make that claim. And then, people can disagree with that claim.

Under Senate rules, Reid's decision on Monday to file cloture on the motion to proceed means two days must pass before a vote on the motion is held. That vote would be on whether to end debate on the motion to proceed.

If the vote succeeds on Wednesday, that will start a 30-hour clock, and when that time expires, a vote on the actual motion to proceed is due.

The two-day and 30-hour timelines are firm, but senators can always agree by unanimous consent to speed them up when everyone agrees. This week, many Senate Republicans were seeking to do just that, to give House Republicans more time to deal with the Senate-passed resolution.