The Collaborative International Dictionary
Square-rigged \Square"-rigged`\ (skw[^a]r"r[i^]gd`), a. (Naut.) Having the sails extended upon yards suspended horizontally by the middle, as distinguished from fore-and-aft sails; thus, a ship and a brig are square-rigged vessels.
Wiktionary
a. (context nautical of a ship English) Having (approximately) square sails rigged onto spars perpendicular to the keel.
WordNet
adj. rigged with square sails as the principal ones
Usage examples of "square-rigged".
With this wind, this head-sea and this current a square-rigged ship might beat up for the island a week on end and gain no eastward distance at all, a waste of time that could not be justified by the vague pointing of a crew of monoglot and largely hostile women, even supposing they pointed at all.
Then John Clarke of the high-sterned Roebuck, a square-rigged flyboat of Dutch design.
She had ten oarports on either side of her hull, as well as a single broad, square-rigged sail, brailed up now that she was in harbor.
The Nenuphar and the Asterias did the same, square-rigged mainsails furled like the Eryngo's, just relying on the triangular sails on their stubby aftmasts for steering in circles.
Fore and aftmasts carried three courses of canvas compared to the Tang's two and that wasn't counting the square-rigged bowsprit and two lateen-rigged mizzens on the aftdeck.
Most of these were long two-decked galleys with high poop decks and one or two square-rigged masts.