(uncountable) Widely cultivated cereal grass, typically Avena sativa. / (countable) Any of the numerous species, varieties, or cultivars of any of several similar grain plants in genus Avena.

A solemn pledge or promise that invokes a deity, a ruler, or another entity (not necessarily present) to attest the truth of a statement or sincerity of one's desire to fulfill a contract or promise.

(archaic) To pledge.

Made from the wood of the oak tree. Also in metaphorical uses, suggesting robustness.

(countable) A deciduous tree with distinctive deeply lobed leaves, acorns, and notably strong wood, typically of England and northeastern North America, included in genus Quercus.

having a rich brown colour, like that of oak wood. / made of oak wood or timber

(wine, transitive) To expose to oak in order for the oak to impart its flavors.

(derogatory) A person, especially a large male, who is clumsy or a simpleton. / (obsolete) An elf's child; a changeling left by fairies or goblins, hence, a deformed or foolish child.

(botany) A tree of the genus Quercus, bearing acorns and having lobed leaves.

A person who rows a boat, either alone or with others.