One plural, two meanings.
49. Other words have one plural form with two meanings,—one corresponding to the singular, the other unlike it.
- custom—customs: (1) habits, ways; (2) revenue duties.
- letter—letters: (1) the alphabet, or epistles; (2) literature.
- number—numbers: (1) figures; (2) poetry, as in the lines,—
I lisped in numbers, for the numbers came.
—Pope.
Tell me not, in mournful numbers.
—Longfellow.
Numbers also means issues, or copies, of a periodical.
- pain—pains: (1) suffering; (2) care, trouble,
- part—parts: (1) divisions; (2) abilities, faculties.
Two classes of compound words.
50. Compound words may be divided into two classes:—
(1) Those whose parts are so closely joined as to constitute one word. These make the last part plural.