Definition of "attitudinizing"

In dining with her brother and with the Dormers, two evenings before, Mrs. Dallow had been moved to exclaim that Peter and Nick knew the most extraordinary people. As regards Peter the attitudinizing girl and her mother now pointed that moral with sufficient vividness; so that there was little arrogance in taking a similar quality for granted in the conceited man at her elbow, who sat there as if he would be capable, from one moment to another, of leaning over the arm of her sofa.

1890, Henry James, The Tragic Muse

With his "hatred of what was theatrical" (1:124) he is put off by the posturings and attitudinizings of the chief actors.

1990, Clyde de L. Ryals, A World of Possibilities: Romantic Irony in Victorian Literature