meaning of gross

[nona m.]

English Error, Elementary Level

ESL/EFL Test #18 "Cat and mouse", question 4

But the cat was too gross for the jar and tried to get out of the jar turning this way and that.

(a) gross
(b) tried
(c) get out

English Error, Elementary Level

ESL/EFL Test #18 "Cat and mouse", answer 4

But the cat was too big for the jar and tried to get out of the jar turning this way and that.

Correct entry: big
The error was: (a) gross
_________________________

what is-gross?

nona m.

[Conchita]

Gross:

http://dictionary.cambridge.org/results.asp?searchword=gross

[Colonelcy]

So?
gross (FAT) adjective
extremely fat or large and ugly:
I'd put on ten kilos and felt gross in my bikini.
big (LARGE) adjective bigger, biggest
large in size or amount:
He's a big man.

I can't find out any differences for this cat.
Could u?