Wiktionary
adv. clearly, without any doubt or complexity.
Wikipedia
Plain and Simple is an album by The Dubliners, the last to be produced by Phil Coulter. Released on the Polydor label in 1973, it featured a number of tracks penned by Coulter himself, including "The Town I Loved So Well", written about The Troubles in his hometown of Derry, and "The Ballad of Ronnie's Mare", a satirical song inspired by Ronnie Drew's equestrian interests. It was the last studio album to feature all five original members of the group.
Usage examples of "plain and simple".
It was, Biagio surmised, a plain and simple place, perfect for a Highland prince.
March is a plain and simple month, raw and honest, not tricked up with any fancy holidays, and I decided that suited my style best.
And they've been acting more like plain and simple outlaws than any warrior society I know of.
The place was officially called a rest home, but, plain and simple, it was a place for the elderly to come to die.
And magick is my gift, plain and simple, like you have yours, Sarel has hers, and Declan and Tori each have theirs.
It was a dream-street, plain and simple, and this had to be a dream.
He had those porno mags same as Hiram, and the sex with the kids, they can say that was part of the pattern, but it all sounds like a power trip to me, plain and simple.