っぱち suffix - meaning and addition of さ suffix

Question

There are several words I've found that end in っぱち. Does the suffix have any special meaning, like がち?

「やけっぱち」
「うそっぱち」
「でこっぱち」

It also seems that these are na-adjectives, and it is possible to add さ (for at least some of them) to turn them into nouns. Is this addition possible for all っぱち adjectives?

Answer 1

There is no special meaning. As one of the linked entries says:

※「～ぱち」は語感に勢いをつけたり、意味を強調するもので、これ自体に意味はない。また、これを付けることで、特に意味が変わるものでもない。

I guess these might be originally coined as a wordplay so that it sounds like a person's name. ～はち/～ぱち (八) was a typical male name-suffix in the Edo period (eg 甚八, 新八). Since ancient times Japanese people often created meaningless phrases just because they sound nice (examples).

I don't think でこっぱち ("forehead") can serve as a na-adjective. For やけっぱち and うそっぱち, it's technically possible to add さ, but it's not common because they already have intense meanings (you don't hear 最高さ often, either).

Answer 2

They are all used as intensifiers for noun there. Therefore っぱち itself doesn't have special meanings like がち(serious?)

Since やけ, うそ and でこ are nouns not adjectivals(na-adjective), You can't add さ to nominalize them.