quadri-, quadra-, quad-, quadru-

1. An algebraic equation of the fourth degree.
2. Any fourth-degree algebraic expression.

1. A set of chromatically tuned stationary bells, usually hung in a tower and played from a keyboard.
2. A tune played on a keyboard connected to a set of stationary bells.
3. A musical instrument consisting of a set of bells in a small tower that a person can play using a keyboard in the same way that a person plays a piano.
4. Etymology: from French carillon, from Old French carignon, "set of four bells"; from Latin quaternionem, "set of four"; from quater, "four times".

Every quarter of an hour; sometimes a reference to pharmaceutical or medical instructions.

A person who is forty years old or forty to forty-nine years old.

A person who is forty to forty-nine years old.

In the Catholic Church liturgical calendar, the first Sunday in Lent.

Quadragesima Sunday is the first Sunday in Lent, about forty days before Easter which is a season of preparation by fasting and prayer, to imitate the example of Christ.

1. A reference to, or suitable for Lent.
2. Consisting of 40; specifically, in regard to a 40-day fast occurring during Lent.

An area in the shape of a four sided formation which is surrounded on all sides by buildings: While on tour in Italy, the tourists passed through an archway into a large quadrangle.

Having four distinct and visible corners or bends: Squares, parallelograms, and rectangles are all quadrangular shapes of buildings or other structures.

Using a four-channel system to record and reproduce sound. The four separate signals may be fed to individual loudspeakers placed in the corners of a room.