Do you know some engineering terms in English? by Markus Wagner; Answer on from credit and thanks for this; level indicator intensity range vertical-amplifier dynamic range control flux density emitter nozzle replacement filter alternate device replacement module programmable logic controller wit...(more)
Well the dictionary definition of ‘wishy-washy’ is:
feeble or insipid in quality and character.
I would consider a wishy-washy person as someone who can lay claim to a few of the following traits. One or two traits would not be really sufficient to label a person wish-washy, but lump a few of these together, and that would be enough to my mind, to make the grade: