1.  squatter(n = noun.person) homesteader, nester - someone who settles lawfully on government land with the intent to acquire title to it;
is a kind of colonist, settler

2.  squatter(n = noun.person) - someone who settles on land without right or title;
is a kind of interloper, intruder, trespasser
Derived form verb squat₃

1.  One who squats; [1913 Webster]
"In such a tract, squatters and trespassers were tolerated to an extent now unknown." [1913 Webster]

2.  See Squat snipe, under Squat. [1913 Webster]

squatter, n.
1 a person who takes unauthorized possession of unoccupied premises.
2 Austral. a a sheep-farmer esp. on a large scale. b hist. a person who gets the right of pasturage from the government on easy terms.
3 a person who settles on new esp. public land without title.
4 a person who squats.

N  inhabitant, resident, residentiary, dweller, indweller, addressee, occupier, occupant, householder, lodger, inmate, tenant, incumbent, sojourner, locum tenens, commorant, settler, squatter, backwoodsman, colonist, islander, denizen, citizen, burgher, oppidan, cockney, cit, townsman, burgess, villager, cottager, cottier, cotter, compatriot, backsettler, boarder, hotel keeper, innkeeper, habitant, paying guest, planter, native, indigene, aborigines, autochthones, Englishman, John Bull, newcomer, aboriginal, American, Caledonian, Cambrian, Canadian, Canuck, downeaster, Scot, Scotchman, Hibernian, Irishman, Welshman, Uncle Sam, Yankee, Brother Jonathan, garrison, crew, population, people, colony, settlement, household, mir, indigenous, native, natal, autochthonal, autochthonous, British, English, American, Canadian, Irish, Scotch, Scottish, Welsh, domestic, domiciliated, domiciled, naturalized, vernacular, domesticated, domiciliary, in the occupation of, garrisoned by, occupied by.