contubernal
Living in close proximity (as though sharing a tent); intimate, familiar.
rare
Tributes between poets, chess champions, couturiers—and novelists—are always hopefully contubernal. All such donors really yearn for others to see that the honored one lives in a tent they share.
Where it comes from
From Latin contubernālis, from contubernium (“companionship in a tent”), from con- + taberna (“a hut, shed, tent”). More at tavern.
Adapted from the Wiktionary entry contubernal (CC BY-SA 4.0).