pigweed

Short definition from Wiktionary

Noun

1. 1
   Any of various weedy plants sometimes used as pig fodder
2. 2
   Any of various weedy plants sometimes used as pig fodder: Amaranthus species.
3. 3
   Any of various weedy plants sometimes used as pig fodder: Chenopodium album, white goosefoot.
4. 4
   Any of various weedy plants sometimes used as pig fodder: Portulaca bicolor, of Australia.
5. 5
   Any of various weedy plants sometimes used as pig fodder: Polygonum aviculare (common knotgrass).
6. 6
   Any of various weedy plants sometimes used as pig fodder: Heracleum sphondylium.