Definition of up :
1. Aloft; on high; in a direction contrary to that of gravity; toward or in a higher place or position; above; - the opposite of down.
2. Aside, so as not to be in use; as, to lay up riches; put up your weapons.
3. From a lower to a higher place on, upon, or along; at a higher situation upon; at the top of.
4. From the coast towards the interior of, as a country; from the mouth towards the source of, as a stream; as, to journey up the country; to sail up the Hudson.
5. In a higher place or position, literally or figuratively; in the state of having arisen; in an upright, or nearly upright, position; standing; mounted on a horse; in a condition of elevation, prominence, advance, proficiency, excitement, insurrection, or the like; -- used with verbs of rest, situation, condition, and the like; as, to be up on a hill; the lid of the box was up; prices are up.
6. Inclining up; tending or going up; upward; as, an up look; an up grade; the up train.
7. The state of being up or above; a state of elevation, prosperity, or the like; - rarely occurring except in the phrase ups and downs.
8. To or in a position of equal advance or equality; not short of, back of, less advanced than, away from, or the like; -- usually followed by to or with; as, to be up to the chin in water; to come up with one's companions; to come up with the enemy; to live up to engagements.
9. To or in a state of completion; completely; wholly; quite; as, in the phrases to eat up; to drink up; to burn up; to sum up; etc.; to shut up the eyes or the mouth; to sew up a rent.
risen, around, outside, toss and turn, concluded, declining, ended, advancing, skyward, abroad, raised, ascending, informed, aged, oncoming, completed, continental, run out, clickable, prospective, best-of-breed, waking, add to, uphill, sprouted, go up, from all sides, raise, over with, awake, Anglo-American, under, back, double, aweigh, age bracket, escalated, happy, bicoastal, improving, bursty, depleted, following, mission accomplished, wakeful, ahead, bouncy, invalid, after, heavenward, abreast, lapsed, onward, knowledgeable, across, gathering, American, forward, step up, along, apart, downriver, through, asynchronous, jacked, acquainted, sleepless, heightened, exhausted, past, about, leading, upwards, backward-compatible, fourfold, conversant, well-informed, compatibility, upbound, exponential, away, finished, upfield, go through the roof, Baltic, upriver, contemporary, into, in the lead, complete, multiply, anglophone, escalate, compatible, backward, au courant, astir, against, bad night, functioning, growing, direct, age, coast-to-coast, peer, insomnia, outdated, higher, versed, dormie, done, elevated, old, elate, conscious, continuing, accumulative, upward, overjoyed, rising, downstream, case-sensitive, active, upstream, down, anymore, soar, downward, Arctic, prepared, by, upwardly, bound for something, current, beyond, increased, up-to-date, age gap, over, graduated, dormy, before, increase, antivirus, at an end, at, elated, terminated, Anglo-Saxon
closed (part of speech: verb)
happening (part of speech: verb)