| reach(noun, deep, gulf, chasm, abyss) |
| rehearing(noun, study, disquisition, delving, examen) |
| reinvestigation(noun, study, disquisition, delving, examen) |
| research(noun, study, disquisition, delving, examen) |
| self-examination(noun, study, disquisition, delving, examen) |
| self-exploration(noun, study, disquisition, delving, examen) |
| self-questioning(noun, study, disquisition, delving, examen) |
| self-reflection(noun, study, disquisition, delving, examen) |
| self-scrutiny(noun, study, disquisition, delving, examen) |
| soul-searching(noun, study, disquisition, delving, examen) |
| spread(noun, deep, gulf, chasm, abyss) |
| stretch(noun, deep, gulf, chasm, abyss) |
| study(noun, disquisition, delving, examen) |
| survey(noun, study, disquisition, delving, examen) |
| trial(noun, study, disquisition, delving, examen) |
| vacancy(noun, deep, gulf, chasm, abyss) |
| vacuity(noun, deep, gulf, chasm, abyss) |
| vacuum(noun, deep, gulf, chasm, abyss) |
| void(noun, deep, gulf, chasm, abyss) |
| waters(noun, form, study, science, field) |