n.1 (in full high treason: see note below) violation by a subject of allegiance to the sovereign or to the State, esp. by attempting to kill or overthrow the sovereign or to overthrow the government.
2 (in full petty treason) hist. murder of one's master or husband, regarded as a form of treason.
Usage:
The crime of petty treason was abolished in 1828; the term high treason, originally distinguished from petty treason, now has the same meaning as treason.
Derivatives:
treasonous adj.
Etymology: ME f. AF treisoun etc., OF tra{iuml}son, f. L traditio handing over (as TRADITION)