For how long has "plead" been used as a verb counterpart to "plea" (noun) even though both words historically have both verb and noun forms?

Solution 1:

According to the following source the use of plea as a verb is a regionalism, while plead as a noun is just a non-standard usage:

In general use, the verb plead means

• to make an earnest appeal, entreaty, or supplication; to beg, implore.

The noun plea has similar legal and general meanings:

plea: - 1. A suit or action at law; the presentation of an action in court. An urgent, emotional request, an entreaty; (also) an unarticulated appeal.

Used as a verb in place of plead, plea can be regarded as a regionalism (Chiefly Eng. regional [north.], and Sc. Now also U.S.):

• If you plea guilty and then later in another hearing say th(at you didn’t do it, can you be charged with perjury? –example of U.S. usage in OED

Using the verb form plead for the noun plea, however, is jarringly nonstandard:

• A Plead to Sinners –title of a poem on a religious site

• A plead to ban homophobia –headline on a college site

• A plead for help –part of a blog title

In each of these examples, the word wanted is plea.

Also from blog.bennettandbennett.com:

When a person admits her guilt in court, she does not plea guilty. She pleads guilty, entering a guilty plea. “Plead” is a verb. “Plea” is a noun.

After a person has admitted his guilt in court, he has not plead (or “pleaed”) guilty. The past tense of “to plead” is “pleaded” or “pled.”

So, referring to regional, non-standard usages, most likely due to the similarity of the spelling of the two terms, it is really hard to find a precise period when it all started. Google Books, if it can be of any real help here, suggest usages of a plead for and plea guilty from the mid-20th century.