Simple past tense and past participle of water down.
Watered-down Sentence Examples
It's straight from the trees; not like that watered down grocery store junk.
These are often very watered down versions of the good stuff.
The oath of abjuration of James was another cause of division, at least till it was watered down in 1719; and by 1726 a revival of the charges of heresy against Simson, with the increase of agitation against the majority of the Assembly who supported patrons, lighted a flame which burned the slight bonds that kept the extremists in union with the kirk.
Soulful with jazz inflections, mature definitely not poppy or watered down.
The top one uses traditional sawdust with watered down PVA.