Managing MMS could be more easier via PowerShell. Today I had to delete hundreds of terms from an MMS. First to check if terms are real, I created for a short script to list them.

function Get-SPManagedMetadataTerm{
[cmdletbinding(SupportsShouldProcess=$true,ConfirmImpact='High')]
param(
 [parameter(Mandatory=$true,Position=0)]$SiteUrl,
 [parameter(Mandatory=$true,Position=1)]$GroupName,
 [parameter(Mandatory=$true,Position=2)]$TermSetName,
 [parameter(Position=3,ValueFromPipeline=$true)]$TermName
 )

Begin{
 [System.reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint") | Out-Null
 $site = New-Object Microsoft.SharePoint.SPSite($SiteUrl)
 $taxonomySession = New-Object Microsoft.SharePoint.Taxonomy.TaxonomySession($site)
 $Group = $taxonomySession.TermStores.Groups | ?{$_.Name -like $GroupName} 
 $TermSet = $Group.TermSets | ?{$_.Name -like "$TermSetName"}
}

Process{
 $Term = $TermSet.Terms | ?{$_.Name -like $TermName}
 if($Term)
 {
 $Term.Name
 }
 else
 {
 "($TermName) could not found!"
 }
}

}

There is a little modification in the script to deleting terms which found.

function Delete-SPManagedMetadataTerm{
[cmdletbinding(SupportsShouldProcess=$true,ConfirmImpact='High')]
param(
 [parameter(Mandatory=$true,Position=0)]$SiteUrl,
 [parameter(Mandatory=$true,Position=1)]$GroupName,
 [parameter(Mandatory=$true,Position=2)]$TermSetName,
 [parameter(Position=3,ValueFromPipeline=$true)]$TermName
 )

Begin{
 [System.reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint") | Out-Null
 $site = New-Object Microsoft.SharePoint.SPSite($SiteUrl)
 $taxonomySession = New-Object Microsoft.SharePoint.Taxonomy.TaxonomySession($site)
 $Group = $taxonomySession.TermStores.Groups | ?{$_.Name -like $GroupName} 
 $TermSet = $Group.TermSets | ?{$_.Name -like $TermSetName}
}

Process{
 $Term = $TermSet.Terms | ?{$_.Name -like $TermName}
 if($Term)
 {
 if($PSCmdlet.ShouldProcess("Term (" + $($Term.Name) + ") will be deleted from ($($Term.TermStore.Name + "/" + $Group.Name + "/" + $TermSet.Name))"))
 {
 $Term.Delete()
 $Term.TermStore.CommitAll()
 "Term (" + $($TermName) + ") has been deleted from ($($Term.TermStore.Name + "/" + $Group.Name + "/" + $TermSet.Name))"
 }
 }
 else
 {
 "($TermName) could not found!"
 }
}

}

The end you could easily check and delete a bunch of terms like this.

$terms = Get-Content terms.txt

$terms| Get-SPManagedMetadataTerm -SiteUrl https://<SiteUrl> -GroupName <GroupName> -TermSetName <TermSetName>

$terms| Delete-SPManagedMetadataTerm -SiteUrl https://<SiteUrl> -GroupName <GroupName> -TermSetName <TermSetName> -Confirm:$false