Marcheshvan (Hebrew: מַרְחֶשְׁוָן‎, Standard Marḥešvan, Tiberian Marḥešwān; from Akkadian waraḫsamnu, literally, 'eighth month'), generally shortened to Cheshvan (חֶשְׁוָן‎, Standard Ḥešvan Tiberian Ḥešwān), is the second month of the civil year (which starts on 1 Tishrei), and the eighth month of the ecclesiastical year (which starts on 1 Nisan) on the Hebrew calendar.

The Hebrew Bible, before the Babylonian Exile, refers to the month as Bul (1 Kings 6:38).

In Sidon, the reference to Bul is also made on the Sarcophagus of Eshmunazar II dated to the early 5th century BC.

In the modern form, with the connection to the roots w-r-ḥ ('moon', 'month') and š-m-n ('eight') no longer apparent, the first two letters מַר (mar) have been re-interpreted as the Hebrew word for 'bitter', alluding to the fact that the month has no holidays or fasts.

[1] In other contexts, the word מַר‎ is attributed to mean droplet,[2] associating this month with the rainy season.