Definition of at :
1. A relation of proximity to, or of presence in or on, something; as, at the door; at your shop; at home; at school; at hand; at sea and on land.
2. Primarily, this word expresses the relations of presence, nearness in place or time, or direction toward; as, at the ninth hour; at the house; to aim at a mark. It is less definite than in or on; at the house may be in or near the house. From this original import are derived all the various uses of at.
3. Relation of direction toward an object or end; as, look at it; to point at one; to aim at a mark; to throw, strike, shoot, wink, mock, laugh at any one.
4. The relation of a point or position in a series, or of degree, rate, or value; as, with the thermometer at 80¡; goods sold at a cheap price; a country estimated at 10, 000 square miles; life is short at the longest.
5. The relation of some employment or action; occupied with; as, at engraving; at husbandry; at play; at work; at meat ( eating); except at puns.
6. The relation of some state or condition; as, at war; at peace; at ease; at your service; at fault; at liberty; at risk; at disadvantage.
7. The relations of source, occasion, reason, consequence, or effect; as, at the sight; at this news; merry at anything; at this declaration; at his command; to demand, require, receive, deserve, endure at your hands.
8. The relations of time, age, or order; as, at ten o'clock; at twenty- one; at once; at first.
direction (part of speech: noun)