get specific property from a workflow definition from a list on sharepoint online using powershell csom

getworkflowdefinition.ps1

#Add references to SharePoint client assemblies and authenticate to Office 365 site - required for CSOM
Add-Type -Path “C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.dll”
Add-Type -Path “C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.Runtime.dll”
Add-Type -Path “C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.WorkflowServices.dll”

#Specify tenant admin and site URL
$SiteUrl = "mysiteurl"
$ListName = "mylistname"
$UserName = "myusername"
$SecurePassword = ConvertTo-SecureString "mypassword" -AsPlainText -Force

#Bind to site collection
$ClientContext = New-Object Microsoft.SharePoint.Client.ClientContext($SiteUrl)
$Credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($UserName, $SecurePassword)
$ClientContext.Credentials = $Credentials
$ClientContext.ExecuteQuery()

# Get List
$List = $ClientContext.Web.Lists.GetByTitle($ListName)
$ClientContext.Load($List)
$ClientContext.ExecuteQuery()

# Get WorkflowServicesManager
$WorkflowServicesManager = New-Object Microsoft.SharePoint.Client.WorkflowServices.WorkflowServicesManager($ClientContext, $ClientContext.Web)
$ClientContext.Load($WorkflowServicesManager)
$ClientContext.ExecuteQuery()

# Get WorkflowSubscriptionService
$WorkflowSubscriptionService = $WorkflowServicesManager.GetWorkflowSubscriptionService()
$ClientContext.Load($WorkflowSubscriptionService)
$ClientContext.ExecuteQuery()

# Get WorkflowSubscriptionCollection of List
$Subscriptions = $WorkflowSubscriptionService.EnumerateSubscriptionsByList($List.Id)
$ClientContext.Load($Subscriptions)
$ClientContext.ExecuteQuery()

# Get WorkflowDeploymentService
$WorkflowDeploymentService = $WorkflowServicesManager.GetWorkflowDeploymentService()
$ClientContext.Load($WorkflowDeploymentService)
$ClientContext.ExecuteQuery()

# Get WorkflowDefinition of First Element in WorkflowSubscriptionCollection
$WorkflowDefinition = $WorkflowDeploymentService.GetDefinition($Subscriptions[0].DefinitionId)
$ClientContext.Load($WorkflowDefinition)
$ClientContext.ExecuteQuery()

# Get mypropertyname in WorkflowDefinition Properties
$WorkflowDefinition.Properties["mypropertyname"]