The ordinal number fifteenth, derived from this letter of the English alphabet, called o and written in the Latin script.

(stenoscript) (a) an initial letter ⟨o⟩

(IRC, acronym of) Operator / (acronym of) Object, see SVO

(humorous) Converts certain words to faux Italian or Spanish. Can be used with Spanish el for expressions such as el stinko.

(unstressed) Contraction of of.. / (obsolete, unstressed) Contraction of on.

(organic chemistry) ortho-

A linking vowel inserted interconsonantally between two morphemes, to ease pronunciation, without contributing to the meaning. It frequently joins words or combining forms of Ancient Greek or Classical Latin origin in the classical compounds of New Latin and international scientific vocabulary, but it can also be used to join modern terms and even abbreviations, either formally or informally.

(pharmacology) a monoclonal antibody derived from a murine source

(medicine) Initialism of alert and oriented.

Initialism of or best offer. / Initialism of offered by owner (commonly seen in real estate sales advertisements)