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