*mutat*

. A ticket for transportation at a reduced rate in consideration of some special circumstance, as increase of travel; specif., a ticket for a certain number of, or for daily, trips between neighboring places at a reduced rate, such as are commonly used by those doing business in a city and living in a suburb. Commutation tickets are excepted from the prohibition against special rates contained in the Interstate Commerce Act of Feb. 4, 1887 (24 Stat. 379), and in 145 U. S. 263 it was held that party tickets were also excepted as being “obviously within the commuting principle.” [ Webster 1913 Suppl. ]

a. [ CF. F. commutatif. ] 1. Relative to exchange; interchangeable; reciprocal. -- Com*mut"a*tive"ly, adv. [ 1913 Webster ]

Rich traders, from their success, are presumed . . . to have cultivated an habitual regard to commutative justice. Burke. [ 1913 Webster ]

2. (Math.) having the property of commutativity. [ PJC ]

n. (Math.) the property of a binary operation or operator such that the result of one term operating on a second is equal to the result of the second term operating on the first. [ GG ]

☞ If the symbol “*” is taken to be a commutative binary operator, then the following equation holds: a*b = b*a A common example is the addition operator for real numbers, “+”: a+b = b+a [ GG ]

n. (Elec.) A piece of apparatus used for reversing the direction of an electrical current; an attachment to certain electrical machines, by means of which alternating currents are made to be continuous or to have the same direction. It may be attached to the end of the spindle of an electric motor, where a brush is in contact sequentially with the parts of the spindle that conduct current to the different windings of the motor. [ 1913 Webster +PJC ]

a. [ L. immutatus, p. p. of immature. ] Unchanged. [ Obs. ] [ 1913 Webster ]

n. [ L. immutatio, from immutare, immutatum, to change. See Immute. ] Change; alteration; mutation. [ R. ] Dr. H. More. [ 1913 Webster ]

n. Interchange; mutual or reciprocal change. [ 1913 Webster ]

n. [ L. mutatio, fr. mutare to change: cf. F. mutation. See Mutable. ] Change; alteration, either in form or qualities. [ 1913 Webster ]

The vicissitude or mutations in the superior globe are no fit matter for this present argument. Bacon. [ 1913 Webster ]

2. (Biol.) Gradual definitely tending variation, such as may be observed in a group of organisms in the fossils of successive geological levels. [ Webster 1913 Suppl. ]

3. (Biol.) (a) As now employed (first by de Vries), a cellular process resulting in a sudden inheritable variation (the offspring differing from its parents in some well-marked character or characters) as distinguished from a gradual variation in which the new characters become fully developed only in the course of many generations. The occurrence of mutations, the selection of strains carrying mutations permitting enhanced survival under prevailing conditions, and the mechanism of hereditary of the characters so appearing, are well-established facts; whether and to what extent the mutation process has played the most important part in the evolution of the existing species and other groups of organisms is an unresolved question. (b) The result of the above process; a suddenly produced variation. Mutations can occur by a change in the fundamental coding sequence of the hereditary material, which in most organisms is DNA, but in some viruses is RNA. It can also occur by rearrangement of an organism's chromosomes. Specific mutations due to a change in DNA sequence have been recognized as causing certain specific hereditary diseases. Certain processes which produce variation in the genotype of an organism, such as sexual mixing of chromosomes in offspring, or artificially induced recombination or introduction of novel genetic material into an organism, are not referred to as mutation. [ Webster 1913 Suppl. +PJC ]

4. (Biol.) a variant strain of an organism in which the hereditary variant property is caused by a mutation{ 3 }. [ Webster 1913 Suppl. ]

adj. Of or pertaining to or marked by genetic mutation{ 3 }. [ WordNet 1.5 ]

n. [ A humorous variation on the term amber mutation. ] (Microbiology, Molecular biology) A mutation in which the base sequence of one of the codons in the messenger RNA has been converted to UAA. Such a mutation may be conditionally suppressed, as can an amber mutation, by the presence of a special transfer RNA. -- ocher mutant, n. [ PJC ]

n. [ L. permutatio: cf. F. permutation. See Permute. ] 1. The act of permuting; exchange of the thing for another; mutual transference; interchange. [ 1913 Webster ]

The violent convulsions and permutations that have been made in property. Burke. [ 1913 Webster ]

2. (Math.) (a) The arrangement of any determinate number of things, as units, objects, letters, etc., in all possible orders, one after the other; -- called also alternation. Cf. Combination, n., 4. (b) Any one of such possible arrangements. [ 1913 Webster ]

3. (Law) Barter; exchange. [ 1913 Webster ]

Permutation lock, a lock in which the parts can be transposed or shifted, so as to require different arrangements of the tumblers on different occasions of unlocking. [ 1913 Webster ]

n. [ F. transmutation, L. transmutatio. See Transmute. ] 1. The act of transmuting, or the state of being transmuted; as, the transmutation of metals. [ 1913 Webster ]

2. (Geom.) The change or reduction of one figure or body into another of the same area or solidity, but of a different form, as of a triangle into a square. [ R. ] [ 1913 Webster ]

3. (Biol.) The change of one species into another, which is assumed to take place in any development theory of life; transformism. Bacon. [ 1913 Webster ]

Transmutation of metals (Alchem.), the conversion of base metals into gold or silver, a process often attempted by the alchemists. See Alchemy, and Philosopher's stone, under Philosopher. [ 1913 Webster ]