The Only Use of

proportion
in
The Great Gatsby

The thing approached the proportions of a scandal — then died away.
p. 57.8

proportions = size or dimensions

Definitions:

(1) (proportion as in: the proportion of females)
relative amount, quantity, or collection
The exact meaning of this sense of proportion is subject to its context. For example:
- "The female proportion is 50%." -- percentage or share
- "The proportion of oil to vinegar." -- ratio (quantity of something relative to the quantity of something else)
- "In the survey, the female proportion said..." -- group
(2) (proportion as in: a problem of large proportion)
size or dimension
(3) (proportion as in: respond in proportion)
appropriate in size, amount, or degree