1 tví-mánuðr
m. the double month, the fifth month in the summer; in the Almanack for 1872 this month begins on the 27th of August and ends on the 25th of September, which answers to the 15th of August to the 15th of September of the old style, Rb. 556; at Tvímánuði or at Tvímánaði sumars, at the time when T. sets in, Grág. i. 152, Ld. 134, Finnb. 298, Grett. 174 new Ed.; boð skyldi vera at Tvímánaði suðr at Ölvusvatni, Ísl. ii. 8, 31; leið nú fram at Tvímánaði sumars, Grett. 150; brúðkaup var í Garpsdal at Tvímánaði, Ld. 134.