un-, not yet, hitherto, still, even now, sign of the ram, 1-3PM, eighth sign of Chinese zodiac
未 centers on something that has not yet happened or is still incomplete: not yet, still, or un-. The zodiac and time-of-day senses are specific cultural applications of the same 'not yet fully developed' idea.
未 is a pictograph of a tree with new branches, representing something still growing and not yet fully formed. This image naturally extends to the idea of 'not yet' or 'still'.
The top short horizontal line is like a new sprout on a tree 木, still small and not yet fully grown. 未 means 'not yet' or 'still'.
For ミ, imagine a tree that is still just a 'meager' sprout: meager -> ミ, and it has not yet become a full tree.
still; as yet; only
the Sheep (eighth sign of the Chinese zodiac); the Ram; the Goat
not yet; un-
(distant) future
less than; under; below
minority (i.e. being under age); minor; underage person
not yet known; unknown; strange
failed attempt (at a crime, suicide, etc.)
not yet fixed; undecided; pending; TBD
widow
unmarried; not yet married
rather; better
unheard-of; unprecedented; unparalleled in history (unparallelled); record-breaking
early dawn; grey of morning; gray of morning
lingering attachment; lingering affection; regret; reluctance; ruefulness
before it happens; previously
unpaid; overdue
uncivilized; uncivilised; primitive; savage
(an) unknown; unknown number; variable
payment default; overdue on a payment
pending; undecided
incomplete; unfinished; imperfect
minor; underage person
unripe; green; immature