Sassenach
/ˈsæsənæk/
Definition 1 of 1
Pro Tip 1/3Scottish Origin
Originally a Gaelic term meant 'Englishman', commonly used by Scots. 
You can tell by his accent, he's a Sassenach.
Pro Tip 2/3Cultural Nuance
It can be friendly teasing or slightly derogatory depending on tone and context. 
Hey Sassenach, fancy a drink?
Pro Tip 3/3Not An Insult
It's not generally used as an insult but be aware of personal and situational sensitivity. 
No offense meant, Sassenach, it's just a local habit.