Definition of fitness
1
: the quality or state of being fit
2
: the capacity of an organism to survive and transmit its genotype to reproductive offspring as compared to competing organisms
also
: the contribution of an allele or genotype to the gene pool of subsequent generations as compared to that of other alleles or genotypes
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Merriam-Webster unabridged
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Time Traveler for fitness
The first known use of fitness was in 1580
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