Definition of "looser"

Therefore we cannot but infer that they did not understand the promise of their Lord as uttered in a sense at variance with the established forms of language, as conveying the doctrine which the clerical binders and loosers of later ages teach.

1844, John Wesley, The Magazine of the Wesleyan Methodist Church

Loosers of topsails and courses, and men stationed at boom tricing-lines, […]

1884, Stephen Bleecker Luce, Aaron Ward, Text-book of Seamanship