Wiktionary
first slips
n. (first slip English)
Usage examples of "first slips".
A sleen would no sooner mark out a girl for return to the pen than three or four others would constantly enter and disappear from his ken, often luring him into their pursuit, while the first slips free, in her turn later perhaps to save another similarly.
And whoever sees the Clark brothers first slips on a bracelet before he can stop her.