After loading the Visual Editor on
https://pt.wikipedia.org/wiki/Quadrado?veaction=edit&debug=1&uselang=pt&useskin=vector

and clicking in the template which shows the text "Wikicionário", in the bottom right corner of the page, I get the following error on console (Google Chrome 28.0.1500.52):

Uncaught TypeError: Cannot read property 'description' of undefined

It comes from the line

if ( data.description !== null ) {

of the following script:
https://bits.wikimedia.org/static-1.22wmf7/extensions/VisualEditor/modules/ve/dm/models/ve.dm.MWTemplateSpecModel.js

Version: unspecified
Severity: normal