tid

Tid is a term with multiple meanings across languages and fields. In Scandinavian languages such as Danish, Norwegian, and Swedish, tid means time or a period, and it appears in everyday phrases and in compound terms referring to duration and timing.

In medicine, t.i.d. is an abbreviation derived from the Latin ter in die, meaning three times a day. It is used to indicate dosing frequency on prescriptions. Because unclear abbreviations can cause errors, some practitioners prefer to spell out “three times daily.”

In computing, tid commonly denotes a thread identifier, the numeric ID that uniquely identifies a thread within a process. The Linux gettid system call provides a thread ID, and many tools and logs display a tid column for threads. In code, a variable named tid is often used to store a thread’s identifier.

In payment processing, TID stands for Terminal Identification (or Terminal ID), a unique code assigned to a payment terminal to identify it in transactions. The acronym can have other meanings in different contexts, so the intended sense of tid or TID depends on the domain in which it is used.