A hunter-gatherer is a member of a group of people who survive by hunting animals and foraging. The term, which originated in anthropological writings of the early 1960s, should have a hyphen, not a virgule or a comma. The plural is hunter-gatherers.
It works as a phrasal adjective (e.g., a hunter-gatherer society), but it’s awkward as a verb. Instead of constructions like (1) they hunted-gathered and (2) they transitioned from hunting-gathering to agriculture, go with (1) they hunted and gathered and (2) they transitioned from hunting and gathering to agriculture.
Examples
In the following examples, hunter-gatherer is used correctly as a compound noun or phrasal adjective:
Dunbar has found 150 to be the sweet spot for hunter-gatherer societies all over the world. [NPR]
… you can swell with all the pride of a hunter-gatherer who has brought home a fresh kill for her young. [Telegraph]
More than 1,000 Penan hunter-gatherers will be taken from their rainforest home and dumped in a vast oil palm plantation … [Survival International]
And, instead of using awkward compounds like hunted-gathered and hunting-gathering, go with the less awkward multiword constructions—for example:
Jack Black has hunted and gathered in Sodom, donned the cape of a Mexican wrestler and been tied down by a thousand Lilliputians. [Los Angeles Times]
There’s just something about hunting and gathering in the great coastal outdoors – in that dreamy ocean air. [Oregon Coast Beach Connection]
