Crossword Dictionary

DECOMPOSE

decompose, break up, break down - v 
separate (substances) into constituent elements or parts 

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Synonyms

break down, corrupt, decay, disintegrate, fester, foul, mold, molder, perish [chiefly British], putrefy, rot, spoil

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Examples

“It separates in the form of small rose-red crystals, which decompose on boiling with water.”

“Nitrous acid and chlorine readily decompose them with liberation of iodine; the same effect being produced when they are heated with concentrated sulphuric acid and manganese dioxide.”

“They readily decompose on heating, and are easily hydrolysed by alkalies; they possess a somewhat more acid character than.”

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Etymology

1750s, "to separate into components," from de- "opposite of" + compose (v.) in the sense of "make or form by uniting two or more things." Sense of "putrefy, become resolved into constituent elements" is by 1777. Related: Decomposed; decomposing.

de- 
active word-forming element in English and in many verbs inherited from French and Latin, from Latin de "down, down from, from, off; concerning" (see de), also used as a prefix in Latin, usually meaning "down, off, away, from among, down from," but also "down to the bottom, totally" hence "completely" (intensive or completive), which is its sense in many English words.

compose (v.)
c. 1400, compousen, "to write" (a book), from Old French composer "put together, compound; adjust, arrange; write" a work (12c.), from com- "with, together" (see com-) + poser "to place," from Late Latin pausare "to cease, lay down" (see pause (n.)).

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