By hook or by crook describes doing something by any means necessary, doing whatever it takes to achieve a goal whether fair or foul. By hook or by crook is a very old phrase, well-known by the fourteenth century. There are various theories as to the origin of this idiom. One theory pertains to the fact that during the Middle Ages, the king owned all the forests and all the trees therein. Peasants were allowed to take any deadwood to use as firewood that they could pull down with a billhook or a shepherd’s crook. Another theory involves two villages named Hook Head and Crooke, located across the Waterford channel from each other. The story goes that Cromwell made the statement that Waterford, Ireland would fall by Hook or by Crooke, meaning an army landed at either of those places would be effective in a siege.
Examples
He has, instead, spent the last four years scheming and amassing funds to win the presidency by hook or by crook. (The Manila Times)
In this sense, it’s fair to say that nonprofit rescue groups today are sometimes operating similarly to the way many commercial breeders were operating in the 1980s, shipping dogs by hook or by crook to get an increasing number of deals done. (The New York Post)
The crowning irony is that the might of an administration headed by a Patel, a party headed by a Patel (since changed), with 7 of the 24 ministers and 42 of the total 182 MLAs from the community, was so fearful of the power of a 22-year-old novice that he had to be kept behind bars by hook or by crook. (The Deccan Herald)
By hook or by crook, the dog covered more than 240 miles in 12 days. (The Sunday Times)