'To feather an oar' definitions:

Definition of 'To feather an oar'

From: GCIDE

Feather \Feath"er\, v. t. [imp. & p. p. Feathered; p. pr. & vb. n. Feathering.]
1. To furnish with a feather or feathers, as an arrow or a cap. [1913 Webster]
An eagle had the ill hap to be struck with an arrow feathered from her own wing. --L'Estrange. [1913 Webster]
2. To adorn, as with feathers; to fringe. [1913 Webster]
A few birches and oaks still feathered the narrow ravines. --Sir W. Scott. [1913 Webster]
3. To render light as a feather; to give wings to.[R.] [1913 Webster]
The Polonian story perhaps may feather some tedious hours. --Loveday. [1913 Webster]
4. To enrich; to exalt; to benefit. [1913 Webster]
They stuck not to say that the king cared not to plume his nobility and people to feather himself. --Bacon. --Dryden. [1913 Webster]
5. To tread, as a cock. --Dryden. [1913 Webster]
To feather one's nest, to provide for one's self especially from property belonging to another, confided to one's care; -- an expression taken from the practice of birds which collect feathers for the lining of their nests.
To feather an oar (Naut), to turn it when it leaves the water so that the blade will be horizontal and offer the least resistance to air while reaching for another stroke.
To tar and feather a person, to smear him with tar and cover him with feathers, as a punishment or an indignity. [1913 Webster]