The Collaborative International Dictionary
Galanga \Ga*lan"ga\, Galangal \Ga*lan"gal\, n.[OE. galingale, OF. galingal, garingal, F. galanga (cf. Sp. galanga), prob. fr. Ar. khalanj[=a]n. ] The pungent aromatic rhizome or tuber of certain East Indian or Chinese species of Alpinia ( Alpinia Galanga and Alpinia officinarum) and of the K[ae]mpferia Galanga), -- all of the Ginger family.
Wikipedia
Alpinia galanga, (also Languas galanga), a plant in the ginger family, is an herb used in cooking, especially in Indonesian and Thai cuisines. It is one of four plants known as galangal, and is differentiated from the others with the common name greater galangal (or simply Thai galangal). The galangals are also called blue ginger or Thai ginger.
A. galanga is called in Indonesian and is the most common form of galangal used in cooking. It is also known as lengkuas and galanga root. In Manipuri, it is known as kanghu. in Myanmar, it is called pa de kaw (ပတဲေကာ). In Cambodia, it is called romdeng (រំដេង).