Bridle: horses. Bridal: weddings.
They will continue to face resistance in some circles, but they are well-established in general usage.
Foolproof = infallible, or impervious to fools.
an unnecessary variant of seldom, which is an adverb.
archaism meaning, essentially, “oh no!” or “how unfortunate!”
It’s not wrong, but it can always give way to thus, which is an adverb in its own right.
= eggcorn for beck and call.