In front, prominently forward.
First in time.
Most importantly.
Positioned in front of (all) others in space, most forward.
Coming before (all) others in time.
Closest to the bow.
Of the highest rank or position; of the greatest importance; of the highest priority.
A variable (usually x, y or z) whose value is to be found.
A person of no identity; a nonentity
Any thing, place, or situation about which nothing is known; an unknown fact or piece of information.
Not known; unidentified; not well known.