Значения термина jokey vein на английском

In a similarly jokey vein, Blake claims to be a better fast bowler than Bolt, who still carries a high self-regard on the cricket pitch.

This note was written in the best jokey vein throughout, beginning, "Miss Corinne Garland, City-DearMadam," and signed, "Your most obliged and obedient servant, Writing-Desk