A mattucashlass is a type of dagger worn concealed in the armpit and primarily used for close combat, part of traditional Scottish male Highland dress.[1] It is also referred to as an armpit dagger[1] or a sleeve dagger in English. In Scots, the alternative name skene-ochil or skene-occles can also be found.[2]
The term mattucashlass derives from Gaelic; Scottish Gaelic: biodag-achlais[3] (in Gaelic; Scottish Gaelic pronounced as /pit̪akˈaxl̪ˠɪʃ/, Gaelic; Scottish Gaelic: biodag meaning "dagger" and Gaelic; Scottish Gaelic: achlais "armpit") presumably via the dialectal by-form Gaelic; Scottish Gaelic: miodag, which is attested in Shaw's 1788 Galic and English Dictionary.[4]
It is also known in Gaelic as the Gaelic; Scottish Gaelic: sgian-achlais (Gaelic; Scottish Gaelic: sgian meaning "knife"),[5] from which the Scots term Scots: skene-ochil or Scots: skene-occles is derived.