Laboring oar, the oar which requires most strength and exertion; often
used figuratively; as, to have, or pull, the laboring oar in some
difficult undertaking.
La*bo"ri*ous (?), a. [L. laboriosus,fr. labor labor: cf. F. laborieux.]
1. Requiring labor, perseverance, or sacrifices; toilsome; tiresome.
Dost thou love watchings, abstinence, or toil, Laborious virtues
all ? Learn these from Cato.
Addison.