Platonic logos :
The Greek word logos is variously translated: "explanation,"
"definition," "characterizartion," "account."
According to the Meno,
a logos of X must:
(a) be applicable to all instances of X (not be too
narrow: a list, such as Meno (and Euthypho) give,
would always be too wide unless exhaustive)
(b) not be applicable to things that are not X (not
be too wide)
(c) not contain in thedefiens (that which does the
defining) any mention of the defiendum (what is to
be defined): see Meno 79b-c.
For example, Socrates gives the following logos of "shape"