adj. Capable of being changed, changeable, mutable
n. Something that can be altered; a variable.
the GNU version of the Collaborative International Dictionary of English
adj. Capable of being altered.
The Century Dictionary and Cyclopedia
Capable of being altered, varied, or made different.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. (of the punishment ordered by a court) capable of being changed to one less severe
adj. capable of being changed or altered in some characteristic
Word Usage
"It was believed that the brain's circuitry was only alterable in certain "critical periods," or brief windows of extreme plasticity; these were thought to occur in childhood, when experience helped to form the brain's circuitry."