sylvan (of the woods) / wild (not domesticated or tamed) / savage; uncivilised / brutal, vicious, merciless

sylvan (one who resides in the woods) / an impolite person / savage (uncivilized or feral human; a barbarian)

wildcat (Felis silvestris)

wild rice (Zizania aquatica)

Muscovy duck (Cairina moschata, a large duck species of the Americas)

(Germanic mythology) Wild Hunt (ghostly hunt that rides across the sky)

ramsons (Allium ursinum, a wild relative of chives)

(organised labour) wildcat strike (strike not authorised by union leaders)

the wild goat (Capra aegagrus)

African hunting dog (Lycaon pictus, a wild dog of Africa)