Mlaḥsô or Mlahsö (Classical Syriac: ܡܠܚܬܝܐ), sometimes referred to as Suryoyo or Surayt, is an extinct or dormant Central Neo-Aramaic language. It was traditionally spoken in eastern Turkey and later also in northeastern Syria by Syriac Orthodox Christians.^[2]

The Mlaḥsô language (Surayt of Mlaḥsô) is closely related to the Surayt of Turabdin but sufficiently different to be considered a separate language, with the syntax of the language having retained more features of Classical Syriac than Turoyo.^[3] It was spoken in the villages of Mlaḥsô (Turkish: Yünlüce, Kurdish: Mela), a village established by two monks from the Tur Abdin mountain range, and in the village of ˁAnşa near Lice, Diyarbakır, Turkey.

The name of the village and the language is derived from the earlier Aramaic word mālaḥtā, 'salt marsh'. The literary Syriac name for the language is Mlaḥthoyo. The native speakers of Mlaḥsô referred to their language simply as Suryô, or Syriac.^[4]

The language was still spoken by a handful of people in the 1970s. The last fluent native speaker of Mlaḥsô, Ibrahim Ḥanna, died in 1998 in Qamishli. His daughters, Munira in Qamishli, Shamiram in Lebanon, and son Dr. Isḥaq Ibrahim in Germany are the only speakers left with some limited native proficiency of the language. Recordings of Ibrahim Ḥanna speaking the language are available on Heidelberg University's Semitic Sound Archive which were done by Otto Jastrow, a prominent German semiticist who is credited as the modern "discoverer" of the language and published the first modern research papers on the existence of Mlaḥsô and its linguistic features.

On 3 May 2009, a historical event in the history of the Mlaḥsô Surayt language took place. The Suroyo TV television station aired the program series Dore w yawmotho, which was about the village Mlaḥsô (and the Tur Abdin village Tamarze). Dr. Isḥaq Ibrahim, the son of Ibrahim Ḥanna, was a guest and spoke in the Mlaḥsô language with his sisters Shamiram in Lebanon and Munira in Qamishli live on the phone. Otto Jastrow was also interviewed regarding his expertise on Mlaḥsô. Turabdin Assyrians/Syriacs viewers and those present at the show could for the first time ever in modern times hear the language live.

The extinction of Mlaḥsô can be attributed to the small amount of original speakers of the language, and them being limited to two isolated villages, resulting in a disproportionate loss of speakers during the Assyrian genocide compared to Turoyo and other variants of Neo-Aramaic.

Mlahsô is phonologically less conservative than Turoyo. This is particularly noticeable in the use of s and z for classical θ and ð. The classical v has been retained though, while it has collapsed into w in Turoyo. Also sometimes y (IPA /j/) replaces ġ. Mlaḥsô also renders the combination of vowel plus y as a single, fronted vowel rather than a diphthong or a glide.

Mlaḥsô is more conservative than Turoyo in grammar and vocabulary, using classical Syriac words and constructions while also preserving the original Aramaic form.^[5]

• Surayt of Turabdin
• Syriac language
• Assyrian people