A Dictionary of Music and Musicians/Close
CLOSE is a word very frequently used in the same sense as Cadence, which see. In ordinary conversation it may very naturally have a little more expansion of meaning than its synonym. It serves to express the ending of a phrase or a theme, or of a whole movement or a section of one, as a fact, and not as denoting the particular succession of chords which are recognised as forming a cadence. Hence the term 'half-close' is very apt, since it expresses not only the most common form of imperfect cadence which ends on the dominant instead of the tonic, but also the position in which that form of close is usually found, viz. not at the end of a phrase or melody, but marking the most usual symmetrical division into two parts in such a manner that the flow of the complete passage is not interrupted.
The word is also used as a verb, where again it has the advantage of the word cadence, since one can say 'Such a passage closes in such a key,' but one cannot say 'Such a passage cadences so'; and if one could, it would hardly express the sense so plainly.