Wordnet 3.0
NOUN (1)
1.
a theory of organic evolution claiming that acquired characteristics are transmitted to offspring;
The Collaborative International Dictionary of English v.0.48:
Lamarckism \La"marck"ism\, n. [From Lamarck, a distinguished
French naturalist.] (Biol.)
The theory that structural variations, characteristic of
species and genera, are produced in animals and plants by the
direct influence of physical environments, and esp., in the
case of animals, by effort, or by use or disuse of certain
organs. It is a discredited theory, not believed by modern
biologists.
[1913 Webster +PJC]
WordNet (r) 3.0 (2006):
Lamarckism
n 1: a theory of organic evolution claiming that acquired
characteristics are transmitted to offspring