Why is the feminine equivalent of an earl a countess rather than an earless?

A comment by Tim Lymington notes that the wife of an earl is a countess. Why is this so? Shouldn't it have been earless? Was this perhaps a conscious decision due to its homography with ear-less?

Did a jarl ever have a jarless? Ah. Perhaps not.

Solution 1:

The male version of countess is sometimes count. From Wikipedia:

The word count came into English from the French comte, itself from Latin comes—in its accusative comitem— meaning "companion", and later "companion of the emperor, delegate of the emperor". The adjective form of the word is "comital". The British and Irish equivalent is an earl (whose wife is a "countess", for lack of an English term).

An earl was originally another title, but later came to be equivalent to count:

An earl is a member of the nobility. The title is Anglo-Saxon, akin to the Scandinavian form jarl, and meant "chieftain", particularly a chieftain set to rule a territory in a king's stead. In Scandinavia, it became obsolete in the Middle Ages and was replaced with duke (hertig/hertug). In later medieval Britain, it became the equivalent of the continental count (in England in the earlier period, it was more akin to duke; in Scotland it assimilated the concept of mormaer). ...

The Norman-derived equivalent "count" was not introduced following the Norman Conquest of England though "countess" was and is used for the female title. As Geoffrey Hughes writes, "It is a likely speculation that the Norman French title 'Count' was abandoned in England in favour of the Germanic 'Earl' […] precisely because of the uncomfortable phonetic proximity to cunt".

Solution 2:

As Hugo cites in his Wikipedia reference, the title of earl is derived from the Anglo-Saxon title. An eorl was the highest rank below the king in pre-Norman England, and there was no female version of the word. Indeed, the only female noble who had a title at all was the cyninge (queen). There existed a kind of abstract title, but it was pretty broad:

ides f (-e/-a) virgin; 2 woman, wife, lady, queen; [it is a word little used except in poetry, and it is supposed by Grimm to have been applied, in the earliest times, like the Greek numfé, to superhuman beings, occupying a position between goddesses and mere women]

In all my reading about the period I have never encountered a female title of rank corresponding to eorl (itself replacing ealdorman). Indeed, even the famous wife of Eorl Leofric of Mercia, whom you know as Lady Godiva (1004-1080), is simply referred to by her given name, Godgifu.

Given that there was no traditional corresponding title of rank, it is not surprising that one should have been borrowed.