cut down

1.  Kill, as in The troops were cut down one by one as they crossed the field. [Early 1800s]
2.  Also, cut down on. Reduce, decrease, as in I want to cut down my caffeine intake, or We have to cut down on our expenses. [Mid-1800s]
3.  cut down to size; knock down to size. Reduce the self-importance of, humble, as in He's so arrogant--I wish someone would cut him down to size, or She really got knocked down to size when her class ranking slipped. [Early 1900s]

Definition: kill; fell
Antonyms: bear, give birth

The verb has 6 meanings:

Meaning #1: cut down on; make a reduction in
  Synonyms: reduce, cut back, trim, trim down, trim back, cut, bring down

Meaning #2: cut with sweeping strokes; as with an ax or machete
  Synonym: slash

Meaning #3: cause to come or go down
  Synonyms: down, knock down, push down, pull down

Meaning #4: intercept (a player), in baseball
  Synonym: cut out

Meaning #5: cut with a blade or mower
  Synonym: mow

Meaning #6: cause to fall by or as if by delivering a blow
  Synonyms: fell, drop, strike down

The adjective cut down has one meaning:

Meaning #1: cut down
  Synonyms: cut, down