A personal assistant was a person who assisted a specific individual.
Whilst working as Yvonne Hartman's secretary, Matthew considered himself to be little more than her personal assistant. (AUDIO: Blind Summit)
There were a number of personal assistants at Torchwood One. Ianto Jones was Yvonne Hartman's; Dean was Kieran Frost's; and Rachel Allan began her career as assistant to Tommy Pierce. She had previously worked as a PA at Hadwin and Bennett. (AUDIO: New Girl)
Bridget Spears was personal assistant to John Frobisher. Lois Habiba later became his junior PA. (TV: Children of Earth: Day One)
Darius Pike was personal assistant to Professor Alistair Gryffen, employed by the Department. (TV: Regeneration)