Clear-Variable removes the value from any existing variable. Clear-Variable does not remove the variable itself. For example, the following example calls Write-Host twice: the first time it writes the variable value; the second time it does not write anything:

PS> $temporaryValue = "Some-Value"
Write-Host $temporaryValue -ForegroundColor Green

Some-Value

PS> Clear-Variable temporaryValue
Write-Host $temporaryValue -ForegroundColor Green