A down pillow has nothing to do with looking down, and neither of them has anything to do with a down payment. Obviously, "down" is a word of many meanings — and thus many ways of conveying its meaning in Spanish. As our newest lesson, on translating "down," explains, before you can translate it to Spanish you often need to understand how it's being used.

Comments
RE; Down as different parts of speech
I believe you mentioned ‘adjective’ twice, one of which (I think) is ‘noun’.
I thought this is what you meant.
Thanks.
— A Student
Context really matters!
By omitting the link I was referring to, ” translating “down” , namely,
http://spanish.about.com/b/2012/12/13/get-these-meanings-down.htm,
one may be misled. Here repeated is the part I’m referring to:
“Down” is one of those simple, everyday words that can be especially challenging to translate to Spanish. … it can function as five parts of speech: most commonly an adverb, but also as a preposition, adjective, verb and adjective [I believe: sic noun].
My apologies for not being clear.
— A Student