peahen means a hen that is a pea (pfau or pavo); and, finally, peafowl means a fowl that is a pea (pfau or pavo). In the same way moorfowl means, not a moor that is connected with a fowl, but a fowl that is connected with a moor.
[§ 421]. It must be clear, ex vi termini, that in every compound word there are two parts; i. e., the whole or part of the original, and the whole or part of the superadded word. In the most perfect forms of inflection there is a third element, viz., a vowel, consonant, or syllable that joins the first word with the second.
In the older forms of all the Gothic languages the presence of this third element was the rule rather than the exception. In the present English it exists in but few words.
a. The -a- in black-a-moor is possibly such a connecting element.
b. The -in- in night-in-gale is most probably such a connecting element. Compare the German form nacht-i-gale, and remember the tendency of vowels to take the sound of -ng before g.
[§ 422]. Improper compounds.—The -s- in words like Thur-s-day, hunt-s-man, may be one of two things.
a. It may be the sign of the genitive case, so that Thursday=Thoris dies. In this case the word is an improper compound, since it is like the word pater-familias in Latin, in a common state of syntactical construction.
b. It may be a connecting sound, like the -i- in nacht-i-gale. Reasons for this view occur in the following fact:—
In the Modern German languages the genitive case of feminine nouns ends otherwise than in -s. Nevertheless, the sound of -s- occurs in composition equally, whether the noun it follows be masculine or feminine. This fact, as far as it goes, makes it convenient to consider the sound in question as a connective rather than a case. Probably, it is neither one nor the other exactly, but the effect of a false analogy.
[§ 423]. Decomposites.—"Composition is the joining together of two words."—See p. [357].