a. [f. TREASON sb. + -ABLE.] Of the nature of treason; characteristic of or involving treason; perfidious, treacherous. (Orig. Sc.)
1375. Barbour, Bruce, V. 550. Þis tratour ay Had in his thocht … How he mycht best bring till ending Þis tresonabill vndirtaking.
c. 1470. Henry, Wallace, XI. 829. Be this tresonabill concord Schyr Jhon suld be off all the Lennox lord.
1546. Reg. Privy Council Scot., I. 32. The tressonabill slauchter of umquhile David Cardinale Archbischop.
1596. Dalrymple, trans. Leslie’s Hist. Scot., X. (S.T.S.), II. 402. Thir trasonable trahitouris.
1634. Documents agst. Prynne (Camden), 27. In a most infamous, daungerous, and treasonable waye.
1675. trans. Camden’s Hist. Eliz., an. 1601. 625. The Earl of Essex … had accused him as an Instigatour of him to this treasonable Attempt.
1741. Richardson, Pamela (1824), I. 110. So, Pamela, we have seized, it seems, your treasonable papers?
1818. Hallam, Mid. Ages, viii. III. (1819), III. 233. Their participation in a treasonable conspiracy being manifest.
1855. Macaulay, Hist. Eng., xvii. IV. 18. The treasonable packet had been found in his bosom.
Hence Treasonableness, treasonable quality or character.
1679. Jenison’s Popish Plot, Pref. 8. Treasonableness in point of Loyalty.
1727. in Bailey, vol. II.
