cannon-proofadj.n.

1588 E. Aggas tr. Caueat for France 24 They whome so manie troubles, namely these last, had made cannon proofe.

1632 G. Hughes Saints Losse 37 It's canon-proofe, and a wall impregnable?

1695 London Gaz. No. 3100/4 The Lodgment on the Right was made Cannon proof.

1756 R. Dinwiddie Let. 27 Dec. in G. Washington Papers (1984) Colonial Ser. IV. 71 Fort Cumberland is..not to be made Cannon proof unless it can be done at a small Expence.

1803 Cobbett's Weekly Polit. Reg. 29 Oct. 608 His boats are neither cannon proof nor sea worthy.

1863 Continental Monthly Mar. 327/2 It appears he had full faith in cannon-proof floating batteries as a means of defence.

1909 W. M. Raine Ridgeway of Montana vii. 100 Once more he had a grip on himself; was sheathed in a cannonproof plate armor of selfishness.

1989 R. L. O'Connell Of Arms & Men vii. 119 Defenders took to building low, sloping dirt ramparts fronted by ditches, presenting attackers with very difficult obstacles which were..largely cannon-proof.

2011 Sunday Times (Nexis) 16 Jan. (Trav. section) 21 You skirt the walls of huge cannon-proof fortifications, built by the kingdom of Piedmont to protect against French invasion in the 19th century.

1601 W. Cornwallis Ess. II. xxix sig. R^v Put him in a Castle by cannon proofe well guarded.

1619 F. Beaumont & J. Fletcher King & No King iii. sig. F3 If I might stand still in Canon proofe, and haue fame fall vpon me, I would refuse it.

1698 J. Crull Antient & Present State Muscovy I. vii. 131 Their Fortifications, made of Earth and Wood,..they account to be better Cannon Proof than Brick'd Walls, but are soon set on fire.