พี่

From Proto-Tai *biːᴮ (“older sibling”). Cognate with Northern Thai ᨻᩦ᩵, Lao ພີ່ (phī), Lü ᦗᦲᧈ (pii¹), Shan ပီႈ (pīi), Ahom 𑜆𑜣 (pii), Zhuang beix, Bouyei bix.

พี่ • (pîi) (classifier คน)

1. elder brother; elder sister.
2. older person.
3. (colloquial) superior; master; leader; boss.
4. used as a title for or term of address to an elder brother, elder sister, or older person; used by such person as a self-reference when addressing a younger brother, younger sister, or younger person.
5. used as an affectionate title for or affectionate term of address to a beloved, older person; used by such person as a self-reference when addressing a beloved, younger person.
   • 2016 June 12, วงษ์เทศ, สุจิตต์, “เจ้าจอมมารดาอำภาใน ร. ๒ เล่นตัวนางกาญจหนาในละครอิเหนา”, in มติชนออนไลน์‎, Bangkok: มติชน, retrieved 2019-03-15:

     สายหยุดพุดจีบจีน เจ้ามีสินพี่มีศักดิ์ คนทั้งวังเขาชังเจ้านัก แต่พี่รักเจ้าคนเดียว

     sǎai-yùt pút-jìip jiin · jâao mii sǐn pîi mii sàk · kon táng wang kǎo chang jâao nák · dtɛ̀ɛ pîi rák jâao kon diao

     [My] dwarf ylang-ylang flower, [my] Chinese crape jasmine, thou art of wealth, I am of worth. They, people throughout the palace, hate thee much, but I am the only one that loveth thee.

6. (colloquial) used as a term of address to a superior, master, leader, or boss; used by such person as a self-reference when addressing a subordinate, inferior, or servant.