You can block a contact to prevent them from calling you on Skype, instant message you or see when you’re online. You can also remove contacts from your contact list completely, including contacts that were suggested to you.
To block a contact:
To unblock a contact:
To remove a contact:
Alternatively, go to your People list and select a contact you want to block, unblock or remove. Press the menu button on your phone or tap the menu icon and select Block contact, Unblock contact or Remove contact.
Learn more about managing contacts in Skype for Android phones.