Definition of "unostentatious"

But terror had overpowered the scanty remains of a body once so powerful, and sensible they were only suffered to remain in this ancient seat by connivance and from compassion, they did not venture upon taking any step which might be construed into an assertion of their ancient rights, contenting themselves with the secret and obscure exercise of their religious ceremonial, in as unostentatious a manner as was possible.

1820, [Walter Scott], chapter XIII, in The Abbot. […], volume I, Edinburgh: […] [James Ballantyne & Co.] for Longman, Hurst, Rees, Orme, and Brown, […]; and for Archibald Constable and Company, and John Ballantyne, […], page 279