archipelagicadj.

/ˌɑːkɪpɪˈladʒɪk/Etymology: < archipelago n. + -ic suffix.
the world > the earth > land > land mass > island > [adjective] > group
1841 49 484 The archipelagic neighbourhoods of Kent Road, etc.
This entry has not yet been fully updated (first published 1885; most recently modified version published online September 2018).