In his journals, James Boswell often referred to titles and professions, and made used of words that are no longer in common use, or which may have changed their meaning somewhat. The definitions below are based on the meaning and context of the words in the second half of the 18th century.
Advocate: An advocate in Scotland performs much the same role as barristers does in England, being able to represent their clients in court in the higher courts. Compare this to solicitors who historically took conduct of litigation and undertook advocacy in the lower courts, but were required to instruct advocates to represent their clients in higher courts. This distinction is no longer entirely valid with the emergence of solicitor advocates who are allowed perform as both a solicitor and an advocate.
Baronet / Bart: A baronet (abbreviated Bart or Bt) is the holder of a hereditary baronetcy awarded by the British Crown. It is the only hereditary honour which is not a peerage; baronets are commoners. A baronet is styled "Sir" like a knight, but ranks above all knighthoods except for the Order of the Garter and the Order of the Thistle. It is now practically obsolete as hereditary honours are no longer recommended.