If Martin really desired his help (Gottlieb could be as modest personally as he was egotistic and swaggering in competitive science), he would make the boy’s career his own.
It furnished excellent antitoxins for diphtheria and tetanus, as well as the purest of official preparations, with the plainest and most official-looking labels on the swaggeringly modest brown bottles.
By this time it was six o’clock of a fine wide August morning, and as he ceased his swift work, as taut nerves slackened, he looked out of his lofty window and was conscious of the world below: bright roofs, jubilant towers, and a high-decked Sound steamer swaggering up the glossy river.
There are no more uses of "swagger" in the book.
Show samples from other sources
The team swaggered onto the court—full of confidence.
The cowboy swaggered into the saloon with his holster unstrapped.