text: As characters and words,  lǎo means "old; senior; aged";  wài means "out; outside; external; outer", and by extension various meanings including "appearance; faraway; distant; non-local; foreign; informal; other; unorthodox".
  is a common colloquial prefix of respect (partly out of the value of seniority conferred), its use dating back to some of the earliest Mandarin vernacular records. In Mandarin, the prefix is well-established enough that it is now inseparably fixed in many words, where its original meaning is lost. For example,  lǎoshī "teacher" is composed of  lǎo and  shī "teacher", and the original word for "teacher"  shī cannot be used alone. Other examples include  lǎotiānyé "(Lord of) Heavens",  lǎoxiāng "fellow townspeople",  lǎohǔ "tiger", and even  lǎoshǔ "mouse", an animal traditionally despised for its cultural character as well as its significant damages to humans.
  In its active use, the prefix  lǎo is most often added to surnames to show respect in informal registers towards anyone not definitively young. This is often contrasted to another prefix  xiǎo "small; little; young", which, added to surnames, shows closeness and friendly affection in informal registers towards anyone more junior and at least slightly younger than the speaker. Another much less common and rather restricted use is attaching  to a descriptor to mark such a person, with a slightly humorous undertone. For example,  lǎowángù "a stubborn one" is composed from  wángù "stubborn".