Definition from Wiktionary, the free dictionary
Alternative forms 
From obsolete Dutch gijben (modern Dutch: gijpen).
- (nautical) To change tack with the wind crossing behind the boat. (Mostly used of boats and other small sailing craft — the corresponding manoeuver in a sailing ship is to wear.)
- (nautical) To shift a fore-and-aft sail suddenly and forcefully from one side to the other, while sailing before the wind. (also jibe.)
- To sneer (see gibe.)
- gybe at: to hesitate, vacillate, or balk when faced with a proposal, plan, or course of action. (Obsolete)
to change tack
gybe (plural gybes)
- The act of gybing.
- A sudden shift of a sail's angle, or a sudden change in the direction that a boat is sailing.
- A sudden change in direction or approach; vacillation.
- A sneer. (see gibe.)