biquadrate

from The Century Dictionary.

• noun Same as biquadratic.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Math.) The fourth power, or the square of the square. Thus 4x4=16, the square of 4, and 16x16=256, the biquadrate of 4.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mathematics The fourth power (the square of a square)

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an algebraic equation of the fourth degree