Definition of Idiom
The narrator uses (and explicitly defines) a period-specific idiom to explain Drouet's flirtatious and sometimes predatory character:
He came within the meaning of a still newer term, which had sprung into general use among Americans in 1880, and which concisely expressed the thought of one whose dress or manners are calculated to elicit the admiration of susceptible young women—a 'masher.'
When introducing Drouet’s attempts to convince people of his wealth and suitability, the narrator employs a period-specific idiom. The idea of “hornswaggling” underscores Drouet's vulnerability, highlighting the ease with which he can be deceived by people who are devious:
Unlock with LitCharts A+A truly deep-dyed villain could have hornswaggled him as readily as he could have flattered a pretty shop-girl.
While backstage, a nervous Carrie is met with consolation from Drouet, who uses an idiom to push her toward giving a more energetic performance:
Unlock with LitCharts A+Carrie revived a little under the drummer’s electrical, nervous condition. "Did I do so very bad?"
"Not a bit. All you need is a little more ginger. Do it as you showed me. Get that toss of your head you had the other night."