weeder

Concise Oxford English Dictionary © 2008 Oxford University Press:
weed/wiːd/

▶noun

• 1 a wild plant growing where it is not wanted and in competition with cultivated plants.

• 2 informal cannabis.

  ■ (the weed) tobacco.

• 3 Brit. informal a contemptibly feeble person.

• 4 informal a leggy, loosely built horse.

▶verb

• 1 remove weeds from.

• 2 (weed something out) remove unwanted items or members from something.

– derivatives
weeder noun,
weedless adjective.

– origin OE wēod (n.), wēodian (v.), of unknown origin.