Blank verse is unrhymed poetry with each line having the same meter - that is each line has the same number of syllables with those syllables creating a regular rhythm. Typically, this is iambic pentameter, which means the line has 10 syllables, and the emphasis on the syllables alternates-every other syllable is stressed.     


First four lines of "Mending Wall" by Robert Frost

Something there is that doesn't love a wall, 
That sends the frozen-ground-swell under it, 
And spills the upper boulders in the sun, 
And makes gaps even two can pass abreast.

First four lines of "Mending Wall" by Robert Frost



Turning and turning in the widening gyre
The falcon cannot hear the falconer;
Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.
         First lines of "Second Coming" by William Butler Yeats

see more https://www.litcharts.com/literary-devices-and-terms/blank-verse