未来【みらい】
(distant) future, future existence, world beyond the grave, the world to come, future (tense)
未知【みち】
not yet known, unknown, strange
未練【みれん】
lingering attachment, lingering affection, regret, reluctance, ruefulness
未熟【みじゅく】
unripe, green, inexperienced, immature, unskilled
未成年【みせいねん】
minor, not of age
未明【みめい】
early dawn, grey of morning, gray of morning
未定【みてい】
not yet fixed, undecided, pending
未遂【みすい】
failed attempt (at a crime, suicide, etc.)
未婚【みこん】
unmarried, not yet married
未然【みぜん】
before it happens, previously
未納【みのう】
payment default, overdue on a payment
未開【みかい】
uncivilized, uncivilised, primitive, savage, undeveloped (land), unexplored (territory, field, etc.), unbloomed (flower)
未完成【みかんせい】
incomplete, unfinished, imperfect
未満【みまん】
less than, under, below
未払い【みはらい】
unpaid, overdue
未解決【みかいけつ】
unsolved, unresolved, unsettled, pending, outstanding
未発表【みはっぴょう】
unpublished, not yet announced
未決【みけつ】
pending, undecided, unconvicted, awaiting judgement
前代未聞【ぜんだいみもん】
unheard-of, unprecedented, unparalleled in history (unparallelled), record-breaking
未知数【みちすう】
(an) unknown, unknown number, variable, unknown quantity, not yet known