crooked hole

crooked hole

[¦kru̇k·əd ¦hōl]
(petroleum engineering)
A borehole drilled at an angle, often because of steeply dipping formations; not to be confused with holes deliberately deviated from the vertical to avoid obstacles or to tap otherwise unavailable reservoirs.
References in classic literature ?
A rusty padlock was fastened on the door, ends of discoloured blinds and curtains flapped drearily against the half-opened upper windows, and the crooked holes cut in the closed shutters below, were black with the darkness of the inside.
The lower receiver must be set up precisely so all holes are straight; crooked holes will prevent the tight fitting pins from installing correctly.