(horticulture) Yielding the same type of plant as that from which a seed was taken.

Purebred; genetically pure. / Genuine. / Of a proper lineage. / Inborn.

plural of true blue

according to one's beliefs.

(uncountable) A nonfiction literary and film genre in which the author examines an actual crime and details the actions of real people. / (countable) A particular work of this genre.

plural of true crime

Curculionidae genera and species.

plural of true airspeed

(aviation) The speed of an aircraft relative to the air mass within which it is flying.

(navigation) Direction relative to true north, typically as contrasted with magnetic bearing.