til

Til is a preposition and adverb in English meaning up to the time of; it functions similarly to until in informal writing. It is commonly written as "'til" with an apostrophe or as "til" without one. In formal writing, many editors prefer the fully spelled-out "until." The form "till" with double l is a separate word and can cause confusion; it is not simply an alternate spelling of the preposition and has its own uses in different contexts (including as a noun meaning a cash register or as a verb meaning to cultivate soil in other senses).

Spelling and style notes: "'til" and "til" are widely used in casual texts, but some style guides discourage omitting the apostrophe. Because "until" is the clearer option in formal prose, many writers choose it for precision. The word "till" (double l) is historically distinct but often mixed up with "til/until" in casual writing. When in doubt for formal documents, revert to "until."

Today I Learned: In online culture, TIL stands for Today I Learned, a popular label on social platforms and knowledge-sharing communities. This acronym is unrelated to the preposition and is typically presented in uppercase as a tag or post category.

In summary, til refers chiefly to the informal contraction of until, with several variant spellings and a potential for confusion with till. It also appears as an acronym in digital discourse, most notably TIL for Today I Learned.