Coptic (Bohairic Coptic: ϯⲙⲉⲧⲣⲉⲙⲛ̀ⲭⲏⲙⲓ, romanized: Timetremənkʰēmi) is a dormant Afroasiatic language. It is a group of closely related Egyptian dialects, representing the most recent developments of the Egyptian language, and historically spoken by the Copts, starting from the third century AD in Roman Egypt. Coptic was supplanted by Arabic as the primary spoken language of Egypt following the Arab conquest of Egypt and was slowly replaced over the centuries.

Coptic has no modern-day native speakers, and no fluent speakers apart from a number of priests, although it remains in daily use as the liturgical language of the Coptic Orthodox Church and of the Coptic Catholic Church. It is written with the Coptic alphabet, a modified form of the Greek alphabet with seven additional letters borrowed from the Demotic Egyptian script.

The major Coptic dialects are Sahidic, Bohairic, Akhmimic, Fayyumic, Lycopolitan (Asyutic), and Oxyrhynchite. Sahidic Coptic was spoken between the cities of Asyut and Oxyrhynchus and flourished as a literary language across Egypt in the period c. 325 – c. 800 AD. The Gnostic texts in the Nag Hammadi library are primarily written in the Sahidic dialect. However, some texts also contain elements of the Subakhmimic (Lycopolitan) dialect, which was also used in Upper Egypt. Bohairic, the dialect of Lower Egypt, gained prominence in the 9th century and is the dialect used by the Coptic Church liturgically.

In Coptic the language is called ϯⲙⲉⲧⲣⲉⲙⲛ̀ⲭⲏⲙⲓ (timetremǹkhēmi) "Egyptian" or ϯⲁⲥⲡⲓ ⲛ̀ⲣⲉⲙⲛ̀ⲭⲏⲙⲓ (tiaspi ǹremǹkhēmi) "the Egyptian language". Coptic also possessed the term ⲅⲩⲡⲧⲓⲟⲥ (gyptios) "Egyptian", derived from Greek Αἰγύπτιος (Aigúptios). This was borrowed into Arabic as ‏قبْط‎ (qibṭ/qubṭ), and from there into the languages of Europe, giving rise to words like French copte, whence the English Copt.

Coptic is spoken liturgically in the Coptic Orthodox and Coptic Catholic Church (along with Modern Standard Arabic). The language is spoken only in Egypt and historically has had little influence outside of the territory, except for monasteries located in Nubia (which straddles modern Egypt and Sudan). Coptic's most noticeable linguistic influence has been on the various dialects of Egyptian Arabic, which is characterised by a Coptic substratum in lexical, morphological, syntactical, and phonological features.

In addition to influencing the grammar, vocabulary and syntax of Egyptian Arabic, Coptic has lent to both Arabic and Modern Hebrew such words as:^{[citation needed]}

A few words of Coptic origin are found in the Greek language; some of the words were later lent to various European languages — such as barge, from Coptic baare (ⲃⲁⲁⲣⲉ, "small boat").^{[citation needed]}

However, most words of Egyptian origin that entered into Greek and subsequently into other European languages came directly from Ancient Egyptian, often Demotic. An example is the Greek oasis (ὄασις), which comes directly from Egyptian wḥꜣt or Demotic wḥj. However, Coptic reborrowed some words of Ancient Egyptian origin into its lexicon, via Greek.^{[citation needed]}