Definition of "assailable"

There’s comfort yet; they [Banquo and Fleance] are assailable; / Then be thou jocund: ere the bat hath flown / His cloister’d flight […] there shall be done / A deed of dreadful note.

c. 1606 (date written), William Shakespeare, “The Tragedie of Macbeth”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene ii]

Plant the ordnance ’gainst the postern, / North of the Eastern tower; for there I deem / The wall is most assailable.

1791, Hannah Brand, Huniades, or, The siege of Belgrave, Act IV, Scene 3, in Plays and Poems, Norwich, 1798, p. 82

Indeed, he lived among a generation of sinners, whose consciences were not assailable by smooth circumlocutions, and whose vices required the scourge and the hot iron.

1849, Edwin Percy Whipple, “South’s Sermons”, in Essays and Reviews, volume I, Boston: Houghton, Mifflin and Company, published 1887, page 385

All that most maddens and torments ; all that stirs up the lees of things ; all truth with malice in it ; all that cracks the sinews and cakes the brain ; all the subtle demonisms of life and thought ; all evil, to crazy Ahab, were visibly personified, and made practically assailable in Moby Dick.

1851 November 14, Herman Melville, chapter 41, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, page 203

What is assailable is that in the process of achieving that goal [equality], you level everybody down.

1993 February 16, James Dao, quoting Michael V. McGill, “Politics Complicates Formulas for Aid to Schools”, in The New York Times‎, page B1