Definition of "warningly"

[…] Moby Dick moved on, still withholding from sight the full terrors of his submerged trunk, entirely hiding the wrenched hideousness of his jaw. But soon the fore part of him slowly rose from the water; for an instant his whole marbleized body formed a high arch […] and warningly waving his bannered flukes in the air, the grand god revealed himself, sounded, and went out of sight.

1851 November 14, Herman Melville, chapter 133, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, page 604

The woman put her finger to her lips, warningly.

1891, Henry Francis Keenan, chapter 13, in The Iron Game‎

The outsides of old Edinburgh churches frightened her, they were of such dark stone, like presences almost the colour of the Castle rock, and were built so warningly with their upraised fingers.

1961, Muriel Spark, chapter 1, in The Prime of Miss Jean Brodie, London: Macmillan