English name. In English, the name Kelsie means-brave.The name Kelsie originated as an English name. The name Kelsie is most often used as a girl name or female name.English Name Meaning-brave.nglish name. In English, the name Kelsie means-brave.The name Kelsie originated as an English name. The name Kelsie is most often used as a girl name or female name. English Name Meaning-brave. Origin-England.