■ verb
1》 make or become smaller or less in amount, degree, or size.
↘boil (a sauce or other liquid) so that it becomes thicker and more concentrated.
↘ chiefly N. Amer. (of a person) lose weight.
↘ Photography make (a negative or print) less dense.
2》 ( ~ someone/thing to ) bring someone or something by force or necessity to (an undesirable state or action).
↘( ~ someone to ) make someone helpless with (shock, anguish, or amusement).
3》 ( ~ something to ) change something to (a simpler or more basic form).
↘convert a fraction to (the form with the lowest terms).
4》 Chemistry cause to combine chemically with hydrogen.
↘undergo or cause to undergo a reaction in which electrons are gained from another substance or molecule. The opposite of oxidize .
5》 restore (a dislocated body part) to its proper position.
6》 archaic besiege and capture (a town or fortress).
Phrases
~d circumstances poverty after relative prosperity.
~ someone to the ranks demote a non-commissioned officer to an ordinary soldier.
Derivatives
~r noun
reducibility noun
reducible adjective
Origin
ME (orig. 'restore', hence 'bring to a different state' and 'bring to a simpler or lower state'): from L. ~re , from re- 'back, again' + ducere 'bring, lead'.