The adjective form of the word festivity is festive. It is quite common to use the adjective form to describe an occasion where people are joyous, happy, and generally having a pleasant time. A person who is in a merry mood could also be described as festive. The venue of a party or other celebration will probably have many brightly colored decorations and this could also be described as festive.

The more commonly used form of the noun is the word festival. A festival has about the same meaning as festivity except that you cannot use it to describe events within a larger party or celebration. To describe the events, you would use the word festivity. In other words, festivities are part of a festival but not the other way around.

A festival can also mean a period of time that is designated for celebrations, feasts, parties, and activities. For example, in Thailand, the period 13-15 April of each year is set aside for the Songkran Festival. It is a celebration of the Thai New Year. Commerce in the country slows down and many festivities take place such as making merit at Buddhist temples, having traditional Thai dance displays, and gathering in the streets to soak each other with water guns, buckets, and whatever else can be used to throw water. In this sense, the Songkran Festival is a celebration of both a religious and personal entertainment nature.

The words festivity or festival can be used to describe an event where musicians, artists, enthusiasts, or performers gather together in one location and share their talents with performances or discussion events. However, festival is used more often in this context. For example, every June in the City of Chicago they have the Chicago Blues Festival where blues and jazz musicians gather to do many performances and celebrate their type of music while promoting it to others who are interested. Then, there is the Albuquerque Balloon Festival where hot air balloonists gather together in the fall of each year to show their vessels and participate in shows and competitions. Officially, the Albuquerque Balloon Festival is name the Albuquerque Balloon Fiesta, using the Spanish version of festival because of the heritage in this New Mexico metropolis.

Sometimes, festivity and festival are shortened by using only the root of the word, fest. Probably the most famous use of fest is in the world-famous German celebration known as Oktoberfest. Many countries around the world have their own mini-Oktoberfests to enjoy some of the festivities that occur in Munich each year.