order Scrophulariales
— Noun
– English
～ used in some classification systems; often included in the order Polemoniales
Oxyuranus scutellatus
— Noun
– English
～ large highly venomous snake of northeastern Australia
off-season
— Noun
– English
～ the season when travel is least active and rates are lowest
order Secotiales
— Noun
– English
～ an order of fungi belonging to the class Gasteromycetes
open secret
— Noun
– English
～ something that is supposed to be secret but is generally known; "their love affair was an open secret"
Ozothamnus secundiflorus
— Noun
– English
～ shrub with white woolly branches and woolly leaves having fragrant flowers forming long sprays; flowers suitable for drying; sometimes placed in genus Helichrysum
OTC security
— Noun
– English
～ a security traded in the over-the-counter market
oil-rich seed
— Noun
– English
～ any of several seeds that yield oil
one-seed
— Adjective
– English
～ having a single seed
one-seeded
— Adjective
– English
～ having a single seed
order Selaginellales
— Noun
– English
～ in some classifications included in Lycopodiales
olfactory sensation
— Noun
– English
～ the sensation that results when olfactory receptors in the nose are stimulated by particular chemicals in gaseous form; "she loved the smell of roses"
Onoclea sensibilis
— Noun
– English
～ beautiful spreading fern of eastern North America and eastern Asia naturalized in western Europe; pinnately divided fronds show a slight tendency to fold when touched; pinnules enclose groups of sori in beadlike lobes
orderly sergeant
— Noun
– English
～ the first sergeant of a company; duties formerly included the conveyance of orders