Definition of "sib"

[…] they are sibber to you than ever Miss Innes was or will be; and if like to bid me, […]

1871 , Ellen Ross, The Wreck of the White Bear: Vol. 1, page 207

seeing that his Majesty is "sibber to him than all the brothers and sons he has in the world." So far, James Haig had played his part with consummate skill.

1881, John Russell, The Haigs of Bemersyde: A Family History, page 144

"You talk about the crook in our Campbell tongue in one breath," said he, "and in the next you would make yourself a Campbell more sib to the chief than I am myself. Don't you think we might put off our little affairs of family history till we find a lady and a child in Strongara?"

1898, Neil Munro, John Splendid: The Tale of a Poor Gentleman and the Little Wars of Lorn, Copp, Clark, page 126

[…] we are so much the sibber to Christ that we suffer; […]

1637 July 6, Letter CLIV to William Glendinning , published in 1821, Joshua Redivivus; Or, Three Hundred and Fifty Two Religious Letters ... To which is Prefixed a Life of the Author, page 199

1701. June 19. Dewar of Lassody against Scott of Spencerfield's Factor and Creditors. […] ; and that creditors seemed to be much sibber to these annualrents than the factors.

1826, Scotland. Court of Session, Mungo Ponton Brown, Supplement to the Dictionary of the Decisions of the Court of Session, page 503

I like my cousins in Holland immensely, but I feel more sib to the Northerners. Your description of Lofoten is fine. I can see them. They must be enchanting in their way, cod's head and tails or no. There is a fine eau de Javelle smack about a Dutch canal, by the way, that takes […]

1906, Oliver Elton, Frederick York Powell: A Life and a Selection from His Letters and Occasional Writings, page 249

But she got up to go, and Domenico obeyed me too in mock meekness, making himself sib and coeval to Hortense, submissive to frowning elder brother, something incestuous in it.

1980, Anthony Burgess, Earthly Powers