FromBrythonic numerals. Literallytethera a (and)dick.

tethera-a-dick

1. (Cumbria)thirteen in Cumbriansheepcounting

• (Borrowdale sheep counting)yan,tyan,tethera,methera,pimp,sethera,lethera,hovera,dovera,dick,yan-a-dick,tyan-a-dick,tethera-a-dick,methera-a-dick,bumfit,yan-a-bumfit,tyan-a-bumfit,tethera-a-bumfit,methera-bumfit,giggot

• Wright, Peter (1995)Cumbrian Chat, Dalesman Publishing Company,→ISBN, page 7
• Deakin, Michael A.B. (2007) Leigh-Lancaster, David, editor,The Name of the Number‎^[1], Australian Council for Educational Research,→ISBN, retrieved2008-05-17, page75
• Varvogli, Aliki (2002)Annie Proulx's The Shipping News: A Reader's Guide‎^[2], Continuum International Publishing Group,→ISBN, retrieved2008-05-17, pages24-25