Definition of "unobtrusively"

He felt not the slightest doubt in his mind that this was the girl who had written him, and, having given an order to the waiter, he started to study her face as unobtrusively as possible.

1920, Herman Cyril McNeile, chapter 1, in Bulldog Drummond

Sometimes she and Miss Baker talked at once, unobtrusively and with a bantering inconsequence that was never quite chatter, that was as cool as their white dresses and their impersonal eyes in the absence of all desire.

1925, F[rancis] Scott Fitzgerald, chapter 1, in The Great Gatsby, New York, N.Y.: Charles Scribner’s Sons, published 1953, page 12

Eudemis moved hastily but as unobtrusively as he could through the gaping crowd[.]

1966, James Workman, The Mad Emperor, Melbourne, Sydney: Scripts, page 40