1) Central 2) Deepest 3) Deepest and most central 4) Farthest inward 5) Furthest inside 6) Inmost 7) Intimate 8) Inward 9) Personal 10) Private 11) Secret 12) Superlatively secret Found on https://www.crosswordclues.com/clue/innermost
In'ner·most` (-mōst`) adjective [ A corruption of inmost due to influence of inner . See Inmost .] Farthest inward; most remote from the outward part; inmost; deepest within. Prov. xviii. 8. Found on http://www.encyclo.co.uk/webster/I/63