Ergo can mean consequently, therefore, accordingly, or hence. It also has a combining form ergo-, usually related to work, i.e. ergonomics, however this originates from the Greek language. The two are commonly mixed up, but entirely separate.
Ergo is believed to have come from the Latin term ex rogo, which means ‘from the direction of.’ It came into English usage in the early 15th century.
The use of ergo alone is not to be confused with cogito, ergo sum, which is commonly used to refer to French philosopher Rene Descartes’ widely debated proposition, ‘I think, therefore I am.’
Ergo literally translates to ‘therefore.’ Examples of use in a sentence include:
Bob was very late, ergo in a lot of trouble.
She was tired, ergo she left the party early.
Please note that ergo is relatively uncommon in informal use, and most commonly written or spoken in a legal or scientific context. The above sentences were written for the purpose of example only.