social

Outgoing is commonly used to describe a person who actively participates in socializing and seeks out opportunities to socialize. A close synonym is extroverted. Outgoing people are often described as social, sociable, or gregarious. Such people are often friendly and talkative.

departing

Outgoing is also used to describe things that are… going out—in other words, leaving or departing. For example, when a new president is elected, you might refer to the one leaving office as the outgoing president. (After departure from office is complete, the terms former and ex- are commonly used.)

This sense of outgoing is commonly used in the context of things like trains and mail. In these contexts, a close synonym is outbound. A similar term is outward-bound.

expenses

In the U.K., the word outgoings is used as another word for expenses or expenditures—money paid out or spent. This is more formally known as disbursement or outlay. Essentially, bills.

Outgoing and sociable are pretty close synonyms. They can both be applied to people (or personalities), and they both suggest that someone thrives in social situations, which they often initiate. However, sociable can be used more broadly to describe situations that involve socializing, as in I had a sociable day—I went to two separate office parties and then happy hour.

The opposite of outgoing in the sense of sociable and extroverted is introverted. Such people are sometimes described as reserved, shy, or bashful.

Just because someone isn’t outgoing doesn’t necessarily mean they are unfriendly, antisocial, or standoffish. Being introverted often just means a person prefers more time to themself and is more comfortable socializing in situations with fewer people.

Opposites of the sense outgoing that means leaving or departing include incoming and inbound. For example, outgoing mail is mail to be sent out; incoming mail is mail that has been delivered.