Most Thai people have a nickname, chuu len in Thai (which translates to 'playname'). But the nickname does not necessarily have a correlation with the formal name. The widespread practice of using nicknames is a reflection of the Thai sabai-sabai culture. Thais have a formal name that usually has a positive and traditional meaning. This name must also conform to proper standards when registered. But at home or with those with whom they have a close relationship, the formal name is not usually used. So, a nickname is created by parents or other family members based on look or actions (hence so many daengs because of a baby's reddish tint right after birth). The nickname is also extended to the workplace. Usually, they use the nickname without the formal preceding title Khun, which is analogous to Mr., Mrs., Miss, or Ms. in English. It demonstrates an informal and close relationship.
Rumor has it that the reason for the nickname is based in the superstition that using the name of a baby will draw the attention of evil spirits, especially when it is said that the baby is cute or beautiful (which is why Thais tend to say that babies are 'ugly').
Nicknames can be grouped into the following categories, with a few examples of each:
KLUAY - Banana
PEN or PUN - Short form of Apple
SOM - Orange
Gem-based (usually girlnames):
LEK - Small
NOI - Little
NIT - A little
TO - Big
YAI - Big
Sky-based (usually girlnames):
Lots of nicknames have a history. For instance, TEE and MUAY can tell us that the person is of Chinese blood. OUN can tell us that during childhood the person was a fat kid. NUENG can tell us that the person is the eldest kid in the family. MOO can tell us that the person was a fat kid, like a pig!
The nickname is also a good starting point to establish small talk. By simply asking the person of their nickname, the following question can probe for the meaning. You will learn lots of personal history. It works very well, particularly with women.
Usually, the native Thai folks have quite a short surname. For example - BOONMEE, SRISAI, etc. However, most of the people who have a long last name are the subsequent generation of a Chinese immigrant. In order to have better understanding, let's look back to the society's history.
Many years ago, when the China mainland transformed the countries political system from a Monarchy to Communist, lots of Chinese left the country seeking a new life opportunity. Many of them selected Thailand as their destination. They started a new life in the Kingdom with prosperity. They still kept their identity by using their Chinese name. Thereafter, their kids, the following generation, were born with a Thai name. However, they still used a Chinese last name like Tang, Lim, Ng, etc. They then came to realize that it was not localized enough to have a Thai name with a Chinese last name. They began to apply for a Thai last name. That is the starting point of this story. When you go to apply for Thai last name, the regulation for registration of the new last name is as follows:
The applicant submits five alternatives to the government officer. Each one has a maximum of 10 Thai characters. The officer will search in the data base for identical last names. The law doesn't allow identical last names to those existing already so hopefully, one of the five alternatives will be unique and can be used. About one month later, the applicant will check with the officer. If there is any duplication, they will need to create a new one and resubmit it again. If there isn't a duplication, then they can use the real NEW last name.
Since Thailand has a lot of immigrant Chinese, subsequent applicants have to create a new name that has a low probability of duplication. Thus, the new surnames just get longer and longer. So next time, if you see Thais who have a long surname, you may want to ask them whether they are really Chinese, or of Chinese descent.